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b3b94faa DT |
1 | /* |
2 | * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. | |
3 | * Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved. | |
4 | * | |
5 | * This copyrighted material is made available to anyone wishing to use, | |
6 | * modify, copy, or redistribute it subject to the terms and conditions | |
7 | * of the GNU General Public License v.2. | |
8 | */ | |
9 | ||
10 | #include <linux/sched.h> | |
11 | #include <linux/slab.h> | |
12 | #include <linux/spinlock.h> | |
13 | #include <linux/completion.h> | |
14 | #include <linux/buffer_head.h> | |
15 | #include <linux/delay.h> | |
16 | #include <linux/sort.h> | |
17 | #include <linux/jhash.h> | |
18 | #include <linux/kref.h> | |
d0dc80db | 19 | #include <linux/kallsyms.h> |
5c676f6d | 20 | #include <linux/gfs2_ondisk.h> |
b3b94faa DT |
21 | #include <asm/semaphore.h> |
22 | #include <asm/uaccess.h> | |
23 | ||
24 | #include "gfs2.h" | |
5c676f6d SW |
25 | #include "lm_interface.h" |
26 | #include "incore.h" | |
b3b94faa DT |
27 | #include "glock.h" |
28 | #include "glops.h" | |
29 | #include "inode.h" | |
30 | #include "lm.h" | |
31 | #include "lops.h" | |
32 | #include "meta_io.h" | |
33 | #include "quota.h" | |
34 | #include "super.h" | |
5c676f6d | 35 | #include "util.h" |
b3b94faa DT |
36 | |
37 | /* Must be kept in sync with the beginning of struct gfs2_glock */ | |
38 | struct glock_plug { | |
39 | struct list_head gl_list; | |
40 | unsigned long gl_flags; | |
41 | }; | |
42 | ||
43 | struct greedy { | |
44 | struct gfs2_holder gr_gh; | |
45 | struct work_struct gr_work; | |
46 | }; | |
47 | ||
48 | typedef void (*glock_examiner) (struct gfs2_glock * gl); | |
49 | ||
50 | /** | |
51 | * relaxed_state_ok - is a requested lock compatible with the current lock mode? | |
52 | * @actual: the current state of the lock | |
53 | * @requested: the lock state that was requested by the caller | |
54 | * @flags: the modifier flags passed in by the caller | |
55 | * | |
56 | * Returns: 1 if the locks are compatible, 0 otherwise | |
57 | */ | |
58 | ||
59 | static inline int relaxed_state_ok(unsigned int actual, unsigned requested, | |
60 | int flags) | |
61 | { | |
62 | if (actual == requested) | |
63 | return 1; | |
64 | ||
65 | if (flags & GL_EXACT) | |
66 | return 0; | |
67 | ||
68 | if (actual == LM_ST_EXCLUSIVE && requested == LM_ST_SHARED) | |
69 | return 1; | |
70 | ||
71 | if (actual != LM_ST_UNLOCKED && (flags & LM_FLAG_ANY)) | |
72 | return 1; | |
73 | ||
74 | return 0; | |
75 | } | |
76 | ||
77 | /** | |
78 | * gl_hash() - Turn glock number into hash bucket number | |
79 | * @lock: The glock number | |
80 | * | |
81 | * Returns: The number of the corresponding hash bucket | |
82 | */ | |
83 | ||
84 | static unsigned int gl_hash(struct lm_lockname *name) | |
85 | { | |
86 | unsigned int h; | |
87 | ||
88 | h = jhash(&name->ln_number, sizeof(uint64_t), 0); | |
89 | h = jhash(&name->ln_type, sizeof(unsigned int), h); | |
90 | h &= GFS2_GL_HASH_MASK; | |
91 | ||
92 | return h; | |
93 | } | |
94 | ||
95 | /** | |
96 | * glock_free() - Perform a few checks and then release struct gfs2_glock | |
97 | * @gl: The glock to release | |
98 | * | |
99 | * Also calls lock module to release its internal structure for this glock. | |
100 | * | |
101 | */ | |
102 | ||
103 | static void glock_free(struct gfs2_glock *gl) | |
104 | { | |
105 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
106 | struct inode *aspace = gl->gl_aspace; | |
107 | ||
108 | gfs2_lm_put_lock(sdp, gl->gl_lock); | |
109 | ||
110 | if (aspace) | |
111 | gfs2_aspace_put(aspace); | |
112 | ||
113 | kmem_cache_free(gfs2_glock_cachep, gl); | |
b3b94faa DT |
114 | } |
115 | ||
116 | /** | |
117 | * gfs2_glock_hold() - increment reference count on glock | |
118 | * @gl: The glock to hold | |
119 | * | |
120 | */ | |
121 | ||
122 | void gfs2_glock_hold(struct gfs2_glock *gl) | |
123 | { | |
124 | kref_get(&gl->gl_ref); | |
125 | } | |
126 | ||
127 | /* All work is done after the return from kref_put() so we | |
128 | can release the write_lock before the free. */ | |
129 | ||
130 | static void kill_glock(struct kref *kref) | |
131 | { | |
132 | struct gfs2_glock *gl = container_of(kref, struct gfs2_glock, gl_ref); | |
133 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
134 | ||
135 | gfs2_assert(sdp, gl->gl_state == LM_ST_UNLOCKED); | |
136 | gfs2_assert(sdp, list_empty(&gl->gl_reclaim)); | |
137 | gfs2_assert(sdp, list_empty(&gl->gl_holders)); | |
138 | gfs2_assert(sdp, list_empty(&gl->gl_waiters1)); | |
139 | gfs2_assert(sdp, list_empty(&gl->gl_waiters2)); | |
140 | gfs2_assert(sdp, list_empty(&gl->gl_waiters3)); | |
141 | } | |
142 | ||
143 | /** | |
144 | * gfs2_glock_put() - Decrement reference count on glock | |
145 | * @gl: The glock to put | |
146 | * | |
147 | */ | |
148 | ||
149 | int gfs2_glock_put(struct gfs2_glock *gl) | |
150 | { | |
151 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
152 | struct gfs2_gl_hash_bucket *bucket = gl->gl_bucket; | |
153 | int rv = 0; | |
154 | ||
f55ab26a | 155 | mutex_lock(&sdp->sd_invalidate_inodes_mutex); |
b3b94faa DT |
156 | |
157 | write_lock(&bucket->hb_lock); | |
158 | if (kref_put(&gl->gl_ref, kill_glock)) { | |
159 | list_del_init(&gl->gl_list); | |
160 | write_unlock(&bucket->hb_lock); | |
161 | glock_free(gl); | |
162 | rv = 1; | |
163 | goto out; | |
164 | } | |
165 | write_unlock(&bucket->hb_lock); | |
166 | out: | |
f55ab26a | 167 | mutex_unlock(&sdp->sd_invalidate_inodes_mutex); |
b3b94faa DT |
168 | return rv; |
169 | } | |
170 | ||
171 | /** | |
172 | * queue_empty - check to see if a glock's queue is empty | |
173 | * @gl: the glock | |
174 | * @head: the head of the queue to check | |
175 | * | |
176 | * This function protects the list in the event that a process already | |
177 | * has a holder on the list and is adding a second holder for itself. | |
178 | * The glmutex lock is what generally prevents processes from working | |
179 | * on the same glock at once, but the special case of adding a second | |
180 | * holder for yourself ("recursive" locking) doesn't involve locking | |
181 | * glmutex, making the spin lock necessary. | |
182 | * | |
183 | * Returns: 1 if the queue is empty | |
184 | */ | |
185 | ||
186 | static inline int queue_empty(struct gfs2_glock *gl, struct list_head *head) | |
187 | { | |
188 | int empty; | |
189 | spin_lock(&gl->gl_spin); | |
190 | empty = list_empty(head); | |
191 | spin_unlock(&gl->gl_spin); | |
192 | return empty; | |
193 | } | |
194 | ||
195 | /** | |
196 | * search_bucket() - Find struct gfs2_glock by lock number | |
197 | * @bucket: the bucket to search | |
198 | * @name: The lock name | |
199 | * | |
200 | * Returns: NULL, or the struct gfs2_glock with the requested number | |
201 | */ | |
202 | ||
203 | static struct gfs2_glock *search_bucket(struct gfs2_gl_hash_bucket *bucket, | |
204 | struct lm_lockname *name) | |
205 | { | |
206 | struct gfs2_glock *gl; | |
207 | ||
208 | list_for_each_entry(gl, &bucket->hb_list, gl_list) { | |
209 | if (test_bit(GLF_PLUG, &gl->gl_flags)) | |
210 | continue; | |
211 | if (!lm_name_equal(&gl->gl_name, name)) | |
212 | continue; | |
213 | ||
214 | kref_get(&gl->gl_ref); | |
215 | ||
216 | return gl; | |
217 | } | |
218 | ||
219 | return NULL; | |
220 | } | |
221 | ||
222 | /** | |
223 | * gfs2_glock_find() - Find glock by lock number | |
224 | * @sdp: The GFS2 superblock | |
225 | * @name: The lock name | |
226 | * | |
227 | * Returns: NULL, or the struct gfs2_glock with the requested number | |
228 | */ | |
229 | ||
230 | struct gfs2_glock *gfs2_glock_find(struct gfs2_sbd *sdp, | |
231 | struct lm_lockname *name) | |
232 | { | |
233 | struct gfs2_gl_hash_bucket *bucket = &sdp->sd_gl_hash[gl_hash(name)]; | |
234 | struct gfs2_glock *gl; | |
235 | ||
236 | read_lock(&bucket->hb_lock); | |
237 | gl = search_bucket(bucket, name); | |
238 | read_unlock(&bucket->hb_lock); | |
239 | ||
240 | return gl; | |
241 | } | |
242 | ||
243 | /** | |
244 | * gfs2_glock_get() - Get a glock, or create one if one doesn't exist | |
245 | * @sdp: The GFS2 superblock | |
246 | * @number: the lock number | |
247 | * @glops: The glock_operations to use | |
248 | * @create: If 0, don't create the glock if it doesn't exist | |
249 | * @glp: the glock is returned here | |
250 | * | |
251 | * This does not lock a glock, just finds/creates structures for one. | |
252 | * | |
253 | * Returns: errno | |
254 | */ | |
255 | ||
256 | int gfs2_glock_get(struct gfs2_sbd *sdp, uint64_t number, | |
257 | struct gfs2_glock_operations *glops, int create, | |
258 | struct gfs2_glock **glp) | |
259 | { | |
260 | struct lm_lockname name; | |
261 | struct gfs2_glock *gl, *tmp; | |
262 | struct gfs2_gl_hash_bucket *bucket; | |
263 | int error; | |
264 | ||
265 | name.ln_number = number; | |
266 | name.ln_type = glops->go_type; | |
267 | bucket = &sdp->sd_gl_hash[gl_hash(&name)]; | |
268 | ||
269 | read_lock(&bucket->hb_lock); | |
270 | gl = search_bucket(bucket, &name); | |
271 | read_unlock(&bucket->hb_lock); | |
272 | ||
273 | if (gl || !create) { | |
274 | *glp = gl; | |
275 | return 0; | |
276 | } | |
277 | ||
278 | gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_KERNEL); | |
279 | if (!gl) | |
280 | return -ENOMEM; | |
281 | ||
282 | memset(gl, 0, sizeof(struct gfs2_glock)); | |
283 | ||
284 | INIT_LIST_HEAD(&gl->gl_list); | |
285 | gl->gl_name = name; | |
286 | kref_init(&gl->gl_ref); | |
287 | ||
288 | spin_lock_init(&gl->gl_spin); | |
289 | ||
290 | gl->gl_state = LM_ST_UNLOCKED; | |
291 | INIT_LIST_HEAD(&gl->gl_holders); | |
292 | INIT_LIST_HEAD(&gl->gl_waiters1); | |
293 | INIT_LIST_HEAD(&gl->gl_waiters2); | |
294 | INIT_LIST_HEAD(&gl->gl_waiters3); | |
295 | ||
296 | gl->gl_ops = glops; | |
297 | ||
298 | gl->gl_bucket = bucket; | |
299 | INIT_LIST_HEAD(&gl->gl_reclaim); | |
300 | ||
301 | gl->gl_sbd = sdp; | |
302 | ||
303 | lops_init_le(&gl->gl_le, &gfs2_glock_lops); | |
304 | INIT_LIST_HEAD(&gl->gl_ail_list); | |
305 | ||
306 | /* If this glock protects actual on-disk data or metadata blocks, | |
307 | create a VFS inode to manage the pages/buffers holding them. */ | |
308 | if (glops == &gfs2_inode_glops || | |
309 | glops == &gfs2_rgrp_glops || | |
310 | glops == &gfs2_meta_glops) { | |
311 | gl->gl_aspace = gfs2_aspace_get(sdp); | |
312 | if (!gl->gl_aspace) { | |
313 | error = -ENOMEM; | |
314 | goto fail; | |
315 | } | |
316 | } | |
317 | ||
318 | error = gfs2_lm_get_lock(sdp, &name, &gl->gl_lock); | |
319 | if (error) | |
320 | goto fail_aspace; | |
321 | ||
b3b94faa DT |
322 | write_lock(&bucket->hb_lock); |
323 | tmp = search_bucket(bucket, &name); | |
324 | if (tmp) { | |
325 | write_unlock(&bucket->hb_lock); | |
326 | glock_free(gl); | |
327 | gl = tmp; | |
328 | } else { | |
329 | list_add_tail(&gl->gl_list, &bucket->hb_list); | |
330 | write_unlock(&bucket->hb_lock); | |
331 | } | |
332 | ||
333 | *glp = gl; | |
334 | ||
335 | return 0; | |
336 | ||
337 | fail_aspace: | |
338 | if (gl->gl_aspace) | |
339 | gfs2_aspace_put(gl->gl_aspace); | |
340 | ||
341 | fail: | |
342 | kmem_cache_free(gfs2_glock_cachep, gl); | |
343 | ||
344 | return error; | |
345 | } | |
346 | ||
347 | /** | |
348 | * gfs2_holder_init - initialize a struct gfs2_holder in the default way | |
349 | * @gl: the glock | |
350 | * @state: the state we're requesting | |
351 | * @flags: the modifier flags | |
352 | * @gh: the holder structure | |
353 | * | |
354 | */ | |
355 | ||
356 | void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, int flags, | |
357 | struct gfs2_holder *gh) | |
358 | { | |
359 | INIT_LIST_HEAD(&gh->gh_list); | |
360 | gh->gh_gl = gl; | |
d0dc80db | 361 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b3b94faa DT |
362 | gh->gh_owner = (flags & GL_NEVER_RECURSE) ? NULL : current; |
363 | gh->gh_state = state; | |
364 | gh->gh_flags = flags; | |
365 | gh->gh_error = 0; | |
366 | gh->gh_iflags = 0; | |
367 | init_completion(&gh->gh_wait); | |
368 | ||
369 | if (gh->gh_state == LM_ST_EXCLUSIVE) | |
370 | gh->gh_flags |= GL_LOCAL_EXCL; | |
371 | ||
372 | gfs2_glock_hold(gl); | |
373 | } | |
374 | ||
375 | /** | |
376 | * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it | |
377 | * @state: the state we're requesting | |
378 | * @flags: the modifier flags | |
379 | * @gh: the holder structure | |
380 | * | |
381 | * Don't mess with the glock. | |
382 | * | |
383 | */ | |
384 | ||
385 | void gfs2_holder_reinit(unsigned int state, int flags, struct gfs2_holder *gh) | |
386 | { | |
387 | gh->gh_state = state; | |
388 | gh->gh_flags = flags; | |
389 | if (gh->gh_state == LM_ST_EXCLUSIVE) | |
390 | gh->gh_flags |= GL_LOCAL_EXCL; | |
391 | ||
392 | gh->gh_iflags &= 1 << HIF_ALLOCED; | |
d0dc80db | 393 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b3b94faa DT |
394 | } |
395 | ||
396 | /** | |
397 | * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference) | |
398 | * @gh: the holder structure | |
399 | * | |
400 | */ | |
401 | ||
402 | void gfs2_holder_uninit(struct gfs2_holder *gh) | |
403 | { | |
404 | gfs2_glock_put(gh->gh_gl); | |
405 | gh->gh_gl = NULL; | |
d0dc80db | 406 | gh->gh_ip = 0; |
b3b94faa DT |
407 | } |
408 | ||
409 | /** | |
410 | * gfs2_holder_get - get a struct gfs2_holder structure | |
411 | * @gl: the glock | |
412 | * @state: the state we're requesting | |
413 | * @flags: the modifier flags | |
414 | * @gfp_flags: __GFP_NOFAIL | |
415 | * | |
416 | * Figure out how big an impact this function has. Either: | |
417 | * 1) Replace it with a cache of structures hanging off the struct gfs2_sbd | |
418 | * 2) Leave it like it is | |
419 | * | |
420 | * Returns: the holder structure, NULL on ENOMEM | |
421 | */ | |
422 | ||
423 | struct gfs2_holder *gfs2_holder_get(struct gfs2_glock *gl, unsigned int state, | |
424 | int flags, gfp_t gfp_flags) | |
425 | { | |
426 | struct gfs2_holder *gh; | |
427 | ||
428 | gh = kmalloc(sizeof(struct gfs2_holder), gfp_flags); | |
429 | if (!gh) | |
430 | return NULL; | |
431 | ||
432 | gfs2_holder_init(gl, state, flags, gh); | |
433 | set_bit(HIF_ALLOCED, &gh->gh_iflags); | |
d0dc80db | 434 | gh->gh_ip = (unsigned long)__builtin_return_address(0); |
b3b94faa DT |
435 | return gh; |
436 | } | |
437 | ||
438 | /** | |
439 | * gfs2_holder_put - get rid of a struct gfs2_holder structure | |
440 | * @gh: the holder structure | |
441 | * | |
442 | */ | |
443 | ||
444 | void gfs2_holder_put(struct gfs2_holder *gh) | |
445 | { | |
446 | gfs2_holder_uninit(gh); | |
447 | kfree(gh); | |
448 | } | |
449 | ||
450 | /** | |
451 | * handle_recurse - put other holder structures (marked recursive) | |
452 | * into the holders list | |
453 | * @gh: the holder structure | |
454 | * | |
455 | */ | |
456 | ||
457 | static void handle_recurse(struct gfs2_holder *gh) | |
458 | { | |
459 | struct gfs2_glock *gl = gh->gh_gl; | |
460 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
461 | struct gfs2_holder *tmp_gh, *safe; | |
462 | int found = 0; | |
463 | ||
fe1bdedc SW |
464 | printk(KERN_INFO "recursion %016llx, %u\n", gl->gl_name.ln_number, |
465 | gl->gl_name.ln_type); | |
466 | ||
b3b94faa DT |
467 | if (gfs2_assert_warn(sdp, gh->gh_owner)) |
468 | return; | |
469 | ||
470 | list_for_each_entry_safe(tmp_gh, safe, &gl->gl_waiters3, gh_list) { | |
471 | if (tmp_gh->gh_owner != gh->gh_owner) | |
472 | continue; | |
473 | ||
474 | gfs2_assert_warn(sdp, | |
475 | test_bit(HIF_RECURSE, &tmp_gh->gh_iflags)); | |
476 | ||
477 | list_move_tail(&tmp_gh->gh_list, &gl->gl_holders); | |
478 | tmp_gh->gh_error = 0; | |
479 | set_bit(HIF_HOLDER, &tmp_gh->gh_iflags); | |
480 | ||
481 | complete(&tmp_gh->gh_wait); | |
482 | ||
483 | found = 1; | |
484 | } | |
485 | ||
486 | gfs2_assert_warn(sdp, found); | |
487 | } | |
488 | ||
489 | /** | |
490 | * do_unrecurse - a recursive holder was just dropped of the waiters3 list | |
491 | * @gh: the holder | |
492 | * | |
493 | * If there is only one other recursive holder, clear its HIF_RECURSE bit. | |
494 | * If there is more than one, leave them alone. | |
495 | * | |
496 | */ | |
497 | ||
498 | static void do_unrecurse(struct gfs2_holder *gh) | |
499 | { | |
500 | struct gfs2_glock *gl = gh->gh_gl; | |
501 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
502 | struct gfs2_holder *tmp_gh, *last_gh = NULL; | |
503 | int found = 0; | |
504 | ||
505 | if (gfs2_assert_warn(sdp, gh->gh_owner)) | |
506 | return; | |
507 | ||
508 | list_for_each_entry(tmp_gh, &gl->gl_waiters3, gh_list) { | |
509 | if (tmp_gh->gh_owner != gh->gh_owner) | |
510 | continue; | |
511 | ||
512 | gfs2_assert_warn(sdp, | |
513 | test_bit(HIF_RECURSE, &tmp_gh->gh_iflags)); | |
514 | ||
515 | if (found) | |
516 | return; | |
517 | ||
518 | found = 1; | |
519 | last_gh = tmp_gh; | |
520 | } | |
521 | ||
522 | if (!gfs2_assert_warn(sdp, found)) | |
523 | clear_bit(HIF_RECURSE, &last_gh->gh_iflags); | |
524 | } | |
525 | ||
526 | /** | |
527 | * rq_mutex - process a mutex request in the queue | |
528 | * @gh: the glock holder | |
529 | * | |
530 | * Returns: 1 if the queue is blocked | |
531 | */ | |
532 | ||
533 | static int rq_mutex(struct gfs2_holder *gh) | |
534 | { | |
535 | struct gfs2_glock *gl = gh->gh_gl; | |
536 | ||
537 | list_del_init(&gh->gh_list); | |
538 | /* gh->gh_error never examined. */ | |
539 | set_bit(GLF_LOCK, &gl->gl_flags); | |
540 | complete(&gh->gh_wait); | |
541 | ||
542 | return 1; | |
543 | } | |
544 | ||
545 | /** | |
546 | * rq_promote - process a promote request in the queue | |
547 | * @gh: the glock holder | |
548 | * | |
549 | * Acquire a new inter-node lock, or change a lock state to more restrictive. | |
550 | * | |
551 | * Returns: 1 if the queue is blocked | |
552 | */ | |
553 | ||
554 | static int rq_promote(struct gfs2_holder *gh) | |
555 | { | |
556 | struct gfs2_glock *gl = gh->gh_gl; | |
557 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
558 | struct gfs2_glock_operations *glops = gl->gl_ops; | |
559 | int recurse; | |
560 | ||
561 | if (!relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) { | |
562 | if (list_empty(&gl->gl_holders)) { | |
563 | gl->gl_req_gh = gh; | |
564 | set_bit(GLF_LOCK, &gl->gl_flags); | |
565 | spin_unlock(&gl->gl_spin); | |
566 | ||
567 | if (atomic_read(&sdp->sd_reclaim_count) > | |
568 | gfs2_tune_get(sdp, gt_reclaim_limit) && | |
569 | !(gh->gh_flags & LM_FLAG_PRIORITY)) { | |
570 | gfs2_reclaim_glock(sdp); | |
571 | gfs2_reclaim_glock(sdp); | |
572 | } | |
573 | ||
574 | glops->go_xmote_th(gl, gh->gh_state, | |
575 | gh->gh_flags); | |
576 | ||
577 | spin_lock(&gl->gl_spin); | |
578 | } | |
579 | return 1; | |
580 | } | |
581 | ||
582 | if (list_empty(&gl->gl_holders)) { | |
583 | set_bit(HIF_FIRST, &gh->gh_iflags); | |
584 | set_bit(GLF_LOCK, &gl->gl_flags); | |
585 | recurse = 0; | |
586 | } else { | |
587 | struct gfs2_holder *next_gh; | |
588 | if (gh->gh_flags & GL_LOCAL_EXCL) | |
589 | return 1; | |
590 | next_gh = list_entry(gl->gl_holders.next, struct gfs2_holder, | |
591 | gh_list); | |
592 | if (next_gh->gh_flags & GL_LOCAL_EXCL) | |
593 | return 1; | |
594 | recurse = test_bit(HIF_RECURSE, &gh->gh_iflags); | |
595 | } | |
596 | ||
597 | list_move_tail(&gh->gh_list, &gl->gl_holders); | |
598 | gh->gh_error = 0; | |
599 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
600 | ||
601 | if (recurse) | |
602 | handle_recurse(gh); | |
603 | ||
604 | complete(&gh->gh_wait); | |
605 | ||
606 | return 0; | |
607 | } | |
608 | ||
609 | /** | |
610 | * rq_demote - process a demote request in the queue | |
611 | * @gh: the glock holder | |
612 | * | |
613 | * Returns: 1 if the queue is blocked | |
614 | */ | |
615 | ||
616 | static int rq_demote(struct gfs2_holder *gh) | |
617 | { | |
618 | struct gfs2_glock *gl = gh->gh_gl; | |
619 | struct gfs2_glock_operations *glops = gl->gl_ops; | |
620 | ||
621 | if (!list_empty(&gl->gl_holders)) | |
622 | return 1; | |
623 | ||
624 | if (gl->gl_state == gh->gh_state || gl->gl_state == LM_ST_UNLOCKED) { | |
625 | list_del_init(&gh->gh_list); | |
626 | gh->gh_error = 0; | |
627 | spin_unlock(&gl->gl_spin); | |
628 | if (test_bit(HIF_DEALLOC, &gh->gh_iflags)) | |
629 | gfs2_holder_put(gh); | |
630 | else | |
631 | complete(&gh->gh_wait); | |
632 | spin_lock(&gl->gl_spin); | |
633 | } else { | |
634 | gl->gl_req_gh = gh; | |
635 | set_bit(GLF_LOCK, &gl->gl_flags); | |
636 | spin_unlock(&gl->gl_spin); | |
637 | ||
638 | if (gh->gh_state == LM_ST_UNLOCKED || | |
639 | gl->gl_state != LM_ST_EXCLUSIVE) | |
640 | glops->go_drop_th(gl); | |
641 | else | |
642 | glops->go_xmote_th(gl, gh->gh_state, gh->gh_flags); | |
643 | ||
644 | spin_lock(&gl->gl_spin); | |
645 | } | |
646 | ||
647 | return 0; | |
648 | } | |
649 | ||
650 | /** | |
651 | * rq_greedy - process a queued request to drop greedy status | |
652 | * @gh: the glock holder | |
653 | * | |
654 | * Returns: 1 if the queue is blocked | |
655 | */ | |
656 | ||
657 | static int rq_greedy(struct gfs2_holder *gh) | |
658 | { | |
659 | struct gfs2_glock *gl = gh->gh_gl; | |
660 | ||
661 | list_del_init(&gh->gh_list); | |
662 | /* gh->gh_error never examined. */ | |
663 | clear_bit(GLF_GREEDY, &gl->gl_flags); | |
664 | spin_unlock(&gl->gl_spin); | |
665 | ||
666 | gfs2_holder_uninit(gh); | |
667 | kfree(container_of(gh, struct greedy, gr_gh)); | |
668 | ||
669 | spin_lock(&gl->gl_spin); | |
670 | ||
671 | return 0; | |
672 | } | |
673 | ||
674 | /** | |
675 | * run_queue - process holder structures on a glock | |
676 | * @gl: the glock | |
677 | * | |
678 | */ | |
679 | ||
680 | static void run_queue(struct gfs2_glock *gl) | |
681 | { | |
682 | struct gfs2_holder *gh; | |
683 | int blocked = 1; | |
684 | ||
685 | for (;;) { | |
686 | if (test_bit(GLF_LOCK, &gl->gl_flags)) | |
687 | break; | |
688 | ||
689 | if (!list_empty(&gl->gl_waiters1)) { | |
690 | gh = list_entry(gl->gl_waiters1.next, | |
691 | struct gfs2_holder, gh_list); | |
692 | ||
693 | if (test_bit(HIF_MUTEX, &gh->gh_iflags)) | |
694 | blocked = rq_mutex(gh); | |
695 | else | |
696 | gfs2_assert_warn(gl->gl_sbd, 0); | |
697 | ||
698 | } else if (!list_empty(&gl->gl_waiters2) && | |
699 | !test_bit(GLF_SKIP_WAITERS2, &gl->gl_flags)) { | |
700 | gh = list_entry(gl->gl_waiters2.next, | |
701 | struct gfs2_holder, gh_list); | |
702 | ||
703 | if (test_bit(HIF_DEMOTE, &gh->gh_iflags)) | |
704 | blocked = rq_demote(gh); | |
705 | else if (test_bit(HIF_GREEDY, &gh->gh_iflags)) | |
706 | blocked = rq_greedy(gh); | |
707 | else | |
708 | gfs2_assert_warn(gl->gl_sbd, 0); | |
709 | ||
710 | } else if (!list_empty(&gl->gl_waiters3)) { | |
711 | gh = list_entry(gl->gl_waiters3.next, | |
712 | struct gfs2_holder, gh_list); | |
713 | ||
714 | if (test_bit(HIF_PROMOTE, &gh->gh_iflags)) | |
715 | blocked = rq_promote(gh); | |
716 | else | |
717 | gfs2_assert_warn(gl->gl_sbd, 0); | |
718 | ||
719 | } else | |
720 | break; | |
721 | ||
722 | if (blocked) | |
723 | break; | |
724 | } | |
725 | } | |
726 | ||
727 | /** | |
728 | * gfs2_glmutex_lock - acquire a local lock on a glock | |
729 | * @gl: the glock | |
730 | * | |
731 | * Gives caller exclusive access to manipulate a glock structure. | |
732 | */ | |
733 | ||
734 | void gfs2_glmutex_lock(struct gfs2_glock *gl) | |
735 | { | |
736 | struct gfs2_holder gh; | |
737 | ||
738 | gfs2_holder_init(gl, 0, 0, &gh); | |
739 | set_bit(HIF_MUTEX, &gh.gh_iflags); | |
740 | ||
741 | spin_lock(&gl->gl_spin); | |
742 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) | |
743 | list_add_tail(&gh.gh_list, &gl->gl_waiters1); | |
744 | else | |
745 | complete(&gh.gh_wait); | |
746 | spin_unlock(&gl->gl_spin); | |
747 | ||
748 | wait_for_completion(&gh.gh_wait); | |
749 | gfs2_holder_uninit(&gh); | |
750 | } | |
751 | ||
752 | /** | |
753 | * gfs2_glmutex_trylock - try to acquire a local lock on a glock | |
754 | * @gl: the glock | |
755 | * | |
756 | * Returns: 1 if the glock is acquired | |
757 | */ | |
758 | ||
759 | int gfs2_glmutex_trylock(struct gfs2_glock *gl) | |
760 | { | |
761 | int acquired = 1; | |
762 | ||
763 | spin_lock(&gl->gl_spin); | |
764 | if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) | |
765 | acquired = 0; | |
766 | spin_unlock(&gl->gl_spin); | |
767 | ||
768 | return acquired; | |
769 | } | |
770 | ||
771 | /** | |
772 | * gfs2_glmutex_unlock - release a local lock on a glock | |
773 | * @gl: the glock | |
774 | * | |
775 | */ | |
776 | ||
777 | void gfs2_glmutex_unlock(struct gfs2_glock *gl) | |
778 | { | |
779 | spin_lock(&gl->gl_spin); | |
780 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
781 | run_queue(gl); | |
782 | spin_unlock(&gl->gl_spin); | |
783 | } | |
784 | ||
785 | /** | |
786 | * handle_callback - add a demote request to a lock's queue | |
787 | * @gl: the glock | |
788 | * @state: the state the caller wants us to change to | |
789 | * | |
790 | */ | |
791 | ||
792 | static void handle_callback(struct gfs2_glock *gl, unsigned int state) | |
793 | { | |
794 | struct gfs2_holder *gh, *new_gh = NULL; | |
795 | ||
796 | restart: | |
797 | spin_lock(&gl->gl_spin); | |
798 | ||
799 | list_for_each_entry(gh, &gl->gl_waiters2, gh_list) { | |
800 | if (test_bit(HIF_DEMOTE, &gh->gh_iflags) && | |
801 | gl->gl_req_gh != gh) { | |
802 | if (gh->gh_state != state) | |
803 | gh->gh_state = LM_ST_UNLOCKED; | |
804 | goto out; | |
805 | } | |
806 | } | |
807 | ||
808 | if (new_gh) { | |
809 | list_add_tail(&new_gh->gh_list, &gl->gl_waiters2); | |
810 | new_gh = NULL; | |
811 | } else { | |
812 | spin_unlock(&gl->gl_spin); | |
813 | ||
814 | new_gh = gfs2_holder_get(gl, state, | |
815 | LM_FLAG_TRY | GL_NEVER_RECURSE, | |
816 | GFP_KERNEL | __GFP_NOFAIL), | |
817 | set_bit(HIF_DEMOTE, &new_gh->gh_iflags); | |
818 | set_bit(HIF_DEALLOC, &new_gh->gh_iflags); | |
819 | ||
820 | goto restart; | |
821 | } | |
822 | ||
823 | out: | |
824 | spin_unlock(&gl->gl_spin); | |
825 | ||
826 | if (new_gh) | |
827 | gfs2_holder_put(new_gh); | |
828 | } | |
829 | ||
830 | /** | |
831 | * state_change - record that the glock is now in a different state | |
832 | * @gl: the glock | |
833 | * @new_state the new state | |
834 | * | |
835 | */ | |
836 | ||
837 | static void state_change(struct gfs2_glock *gl, unsigned int new_state) | |
838 | { | |
b3b94faa DT |
839 | int held1, held2; |
840 | ||
841 | held1 = (gl->gl_state != LM_ST_UNLOCKED); | |
842 | held2 = (new_state != LM_ST_UNLOCKED); | |
843 | ||
844 | if (held1 != held2) { | |
6a6b3d01 | 845 | if (held2) |
b3b94faa | 846 | gfs2_glock_hold(gl); |
6a6b3d01 | 847 | else |
b3b94faa | 848 | gfs2_glock_put(gl); |
b3b94faa DT |
849 | } |
850 | ||
851 | gl->gl_state = new_state; | |
852 | } | |
853 | ||
854 | /** | |
855 | * xmote_bh - Called after the lock module is done acquiring a lock | |
856 | * @gl: The glock in question | |
857 | * @ret: the int returned from the lock module | |
858 | * | |
859 | */ | |
860 | ||
861 | static void xmote_bh(struct gfs2_glock *gl, unsigned int ret) | |
862 | { | |
863 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
864 | struct gfs2_glock_operations *glops = gl->gl_ops; | |
865 | struct gfs2_holder *gh = gl->gl_req_gh; | |
866 | int prev_state = gl->gl_state; | |
867 | int op_done = 1; | |
868 | ||
869 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); | |
870 | gfs2_assert_warn(sdp, queue_empty(gl, &gl->gl_holders)); | |
871 | gfs2_assert_warn(sdp, !(ret & LM_OUT_ASYNC)); | |
872 | ||
873 | state_change(gl, ret & LM_OUT_ST_MASK); | |
874 | ||
875 | if (prev_state != LM_ST_UNLOCKED && !(ret & LM_OUT_CACHEABLE)) { | |
876 | if (glops->go_inval) | |
877 | glops->go_inval(gl, DIO_METADATA | DIO_DATA); | |
878 | } else if (gl->gl_state == LM_ST_DEFERRED) { | |
879 | /* We might not want to do this here. | |
880 | Look at moving to the inode glops. */ | |
881 | if (glops->go_inval) | |
882 | glops->go_inval(gl, DIO_DATA); | |
883 | } | |
884 | ||
885 | /* Deal with each possible exit condition */ | |
886 | ||
887 | if (!gh) | |
888 | gl->gl_stamp = jiffies; | |
889 | ||
890 | else if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) { | |
891 | spin_lock(&gl->gl_spin); | |
892 | list_del_init(&gh->gh_list); | |
893 | gh->gh_error = -EIO; | |
894 | if (test_bit(HIF_RECURSE, &gh->gh_iflags)) | |
895 | do_unrecurse(gh); | |
896 | spin_unlock(&gl->gl_spin); | |
897 | ||
898 | } else if (test_bit(HIF_DEMOTE, &gh->gh_iflags)) { | |
899 | spin_lock(&gl->gl_spin); | |
900 | list_del_init(&gh->gh_list); | |
901 | if (gl->gl_state == gh->gh_state || | |
902 | gl->gl_state == LM_ST_UNLOCKED) | |
903 | gh->gh_error = 0; | |
904 | else { | |
905 | if (gfs2_assert_warn(sdp, gh->gh_flags & | |
906 | (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) == -1) | |
907 | fs_warn(sdp, "ret = 0x%.8X\n", ret); | |
908 | gh->gh_error = GLR_TRYFAILED; | |
909 | } | |
910 | spin_unlock(&gl->gl_spin); | |
911 | ||
912 | if (ret & LM_OUT_CANCELED) | |
913 | handle_callback(gl, LM_ST_UNLOCKED); /* Lame */ | |
914 | ||
915 | } else if (ret & LM_OUT_CANCELED) { | |
916 | spin_lock(&gl->gl_spin); | |
917 | list_del_init(&gh->gh_list); | |
918 | gh->gh_error = GLR_CANCELED; | |
919 | if (test_bit(HIF_RECURSE, &gh->gh_iflags)) | |
920 | do_unrecurse(gh); | |
921 | spin_unlock(&gl->gl_spin); | |
922 | ||
923 | } else if (relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) { | |
924 | spin_lock(&gl->gl_spin); | |
925 | list_move_tail(&gh->gh_list, &gl->gl_holders); | |
926 | gh->gh_error = 0; | |
927 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
928 | spin_unlock(&gl->gl_spin); | |
929 | ||
930 | set_bit(HIF_FIRST, &gh->gh_iflags); | |
931 | ||
932 | op_done = 0; | |
933 | ||
934 | } else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) { | |
935 | spin_lock(&gl->gl_spin); | |
936 | list_del_init(&gh->gh_list); | |
937 | gh->gh_error = GLR_TRYFAILED; | |
938 | if (test_bit(HIF_RECURSE, &gh->gh_iflags)) | |
939 | do_unrecurse(gh); | |
940 | spin_unlock(&gl->gl_spin); | |
941 | ||
942 | } else { | |
943 | if (gfs2_assert_withdraw(sdp, 0) == -1) | |
944 | fs_err(sdp, "ret = 0x%.8X\n", ret); | |
945 | } | |
946 | ||
947 | if (glops->go_xmote_bh) | |
948 | glops->go_xmote_bh(gl); | |
949 | ||
950 | if (op_done) { | |
951 | spin_lock(&gl->gl_spin); | |
952 | gl->gl_req_gh = NULL; | |
953 | gl->gl_req_bh = NULL; | |
954 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
955 | run_queue(gl); | |
956 | spin_unlock(&gl->gl_spin); | |
957 | } | |
958 | ||
959 | gfs2_glock_put(gl); | |
960 | ||
961 | if (gh) { | |
962 | if (test_bit(HIF_DEALLOC, &gh->gh_iflags)) | |
963 | gfs2_holder_put(gh); | |
964 | else | |
965 | complete(&gh->gh_wait); | |
966 | } | |
967 | } | |
968 | ||
969 | /** | |
970 | * gfs2_glock_xmote_th - Call into the lock module to acquire or change a glock | |
971 | * @gl: The glock in question | |
972 | * @state: the requested state | |
973 | * @flags: modifier flags to the lock call | |
974 | * | |
975 | */ | |
976 | ||
977 | void gfs2_glock_xmote_th(struct gfs2_glock *gl, unsigned int state, int flags) | |
978 | { | |
979 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
980 | struct gfs2_glock_operations *glops = gl->gl_ops; | |
981 | int lck_flags = flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB | | |
982 | LM_FLAG_NOEXP | LM_FLAG_ANY | | |
983 | LM_FLAG_PRIORITY); | |
984 | unsigned int lck_ret; | |
985 | ||
986 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); | |
987 | gfs2_assert_warn(sdp, queue_empty(gl, &gl->gl_holders)); | |
988 | gfs2_assert_warn(sdp, state != LM_ST_UNLOCKED); | |
989 | gfs2_assert_warn(sdp, state != gl->gl_state); | |
990 | ||
991 | if (gl->gl_state == LM_ST_EXCLUSIVE) { | |
992 | if (glops->go_sync) | |
993 | glops->go_sync(gl, | |
994 | DIO_METADATA | DIO_DATA | DIO_RELEASE); | |
995 | } | |
996 | ||
997 | gfs2_glock_hold(gl); | |
998 | gl->gl_req_bh = xmote_bh; | |
999 | ||
b3b94faa DT |
1000 | lck_ret = gfs2_lm_lock(sdp, gl->gl_lock, gl->gl_state, state, |
1001 | lck_flags); | |
1002 | ||
1003 | if (gfs2_assert_withdraw(sdp, !(lck_ret & LM_OUT_ERROR))) | |
1004 | return; | |
1005 | ||
1006 | if (lck_ret & LM_OUT_ASYNC) | |
1007 | gfs2_assert_warn(sdp, lck_ret == LM_OUT_ASYNC); | |
1008 | else | |
1009 | xmote_bh(gl, lck_ret); | |
1010 | } | |
1011 | ||
1012 | /** | |
1013 | * drop_bh - Called after a lock module unlock completes | |
1014 | * @gl: the glock | |
1015 | * @ret: the return status | |
1016 | * | |
1017 | * Doesn't wake up the process waiting on the struct gfs2_holder (if any) | |
1018 | * Doesn't drop the reference on the glock the top half took out | |
1019 | * | |
1020 | */ | |
1021 | ||
1022 | static void drop_bh(struct gfs2_glock *gl, unsigned int ret) | |
1023 | { | |
1024 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1025 | struct gfs2_glock_operations *glops = gl->gl_ops; | |
1026 | struct gfs2_holder *gh = gl->gl_req_gh; | |
1027 | ||
1028 | clear_bit(GLF_PREFETCH, &gl->gl_flags); | |
1029 | ||
1030 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); | |
1031 | gfs2_assert_warn(sdp, queue_empty(gl, &gl->gl_holders)); | |
1032 | gfs2_assert_warn(sdp, !ret); | |
1033 | ||
1034 | state_change(gl, LM_ST_UNLOCKED); | |
1035 | ||
1036 | if (glops->go_inval) | |
1037 | glops->go_inval(gl, DIO_METADATA | DIO_DATA); | |
1038 | ||
1039 | if (gh) { | |
1040 | spin_lock(&gl->gl_spin); | |
1041 | list_del_init(&gh->gh_list); | |
1042 | gh->gh_error = 0; | |
1043 | spin_unlock(&gl->gl_spin); | |
1044 | } | |
1045 | ||
1046 | if (glops->go_drop_bh) | |
1047 | glops->go_drop_bh(gl); | |
1048 | ||
1049 | spin_lock(&gl->gl_spin); | |
1050 | gl->gl_req_gh = NULL; | |
1051 | gl->gl_req_bh = NULL; | |
1052 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
1053 | run_queue(gl); | |
1054 | spin_unlock(&gl->gl_spin); | |
1055 | ||
1056 | gfs2_glock_put(gl); | |
1057 | ||
1058 | if (gh) { | |
1059 | if (test_bit(HIF_DEALLOC, &gh->gh_iflags)) | |
1060 | gfs2_holder_put(gh); | |
1061 | else | |
1062 | complete(&gh->gh_wait); | |
1063 | } | |
1064 | } | |
1065 | ||
1066 | /** | |
1067 | * gfs2_glock_drop_th - call into the lock module to unlock a lock | |
1068 | * @gl: the glock | |
1069 | * | |
1070 | */ | |
1071 | ||
1072 | void gfs2_glock_drop_th(struct gfs2_glock *gl) | |
1073 | { | |
1074 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1075 | struct gfs2_glock_operations *glops = gl->gl_ops; | |
1076 | unsigned int ret; | |
1077 | ||
1078 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); | |
1079 | gfs2_assert_warn(sdp, queue_empty(gl, &gl->gl_holders)); | |
1080 | gfs2_assert_warn(sdp, gl->gl_state != LM_ST_UNLOCKED); | |
1081 | ||
1082 | if (gl->gl_state == LM_ST_EXCLUSIVE) { | |
1083 | if (glops->go_sync) | |
1084 | glops->go_sync(gl, | |
1085 | DIO_METADATA | DIO_DATA | DIO_RELEASE); | |
1086 | } | |
1087 | ||
1088 | gfs2_glock_hold(gl); | |
1089 | gl->gl_req_bh = drop_bh; | |
1090 | ||
b3b94faa DT |
1091 | ret = gfs2_lm_unlock(sdp, gl->gl_lock, gl->gl_state); |
1092 | ||
1093 | if (gfs2_assert_withdraw(sdp, !(ret & LM_OUT_ERROR))) | |
1094 | return; | |
1095 | ||
1096 | if (!ret) | |
1097 | drop_bh(gl, ret); | |
1098 | else | |
1099 | gfs2_assert_warn(sdp, ret == LM_OUT_ASYNC); | |
1100 | } | |
1101 | ||
1102 | /** | |
1103 | * do_cancels - cancel requests for locks stuck waiting on an expire flag | |
1104 | * @gh: the LM_FLAG_PRIORITY holder waiting to acquire the lock | |
1105 | * | |
1106 | * Don't cancel GL_NOCANCEL requests. | |
1107 | */ | |
1108 | ||
1109 | static void do_cancels(struct gfs2_holder *gh) | |
1110 | { | |
1111 | struct gfs2_glock *gl = gh->gh_gl; | |
1112 | ||
1113 | spin_lock(&gl->gl_spin); | |
1114 | ||
1115 | while (gl->gl_req_gh != gh && | |
1116 | !test_bit(HIF_HOLDER, &gh->gh_iflags) && | |
1117 | !list_empty(&gh->gh_list)) { | |
1118 | if (gl->gl_req_bh && | |
1119 | !(gl->gl_req_gh && | |
1120 | (gl->gl_req_gh->gh_flags & GL_NOCANCEL))) { | |
1121 | spin_unlock(&gl->gl_spin); | |
1122 | gfs2_lm_cancel(gl->gl_sbd, gl->gl_lock); | |
1123 | msleep(100); | |
1124 | spin_lock(&gl->gl_spin); | |
1125 | } else { | |
1126 | spin_unlock(&gl->gl_spin); | |
1127 | msleep(100); | |
1128 | spin_lock(&gl->gl_spin); | |
1129 | } | |
1130 | } | |
1131 | ||
1132 | spin_unlock(&gl->gl_spin); | |
1133 | } | |
1134 | ||
1135 | /** | |
1136 | * glock_wait_internal - wait on a glock acquisition | |
1137 | * @gh: the glock holder | |
1138 | * | |
1139 | * Returns: 0 on success | |
1140 | */ | |
1141 | ||
1142 | static int glock_wait_internal(struct gfs2_holder *gh) | |
1143 | { | |
1144 | struct gfs2_glock *gl = gh->gh_gl; | |
1145 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1146 | struct gfs2_glock_operations *glops = gl->gl_ops; | |
1147 | ||
1148 | if (test_bit(HIF_ABORTED, &gh->gh_iflags)) | |
1149 | return -EIO; | |
1150 | ||
1151 | if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) { | |
1152 | spin_lock(&gl->gl_spin); | |
1153 | if (gl->gl_req_gh != gh && | |
1154 | !test_bit(HIF_HOLDER, &gh->gh_iflags) && | |
1155 | !list_empty(&gh->gh_list)) { | |
1156 | list_del_init(&gh->gh_list); | |
1157 | gh->gh_error = GLR_TRYFAILED; | |
1158 | if (test_bit(HIF_RECURSE, &gh->gh_iflags)) | |
1159 | do_unrecurse(gh); | |
1160 | run_queue(gl); | |
1161 | spin_unlock(&gl->gl_spin); | |
1162 | return gh->gh_error; | |
1163 | } | |
1164 | spin_unlock(&gl->gl_spin); | |
1165 | } | |
1166 | ||
1167 | if (gh->gh_flags & LM_FLAG_PRIORITY) | |
1168 | do_cancels(gh); | |
1169 | ||
1170 | wait_for_completion(&gh->gh_wait); | |
1171 | ||
1172 | if (gh->gh_error) | |
1173 | return gh->gh_error; | |
1174 | ||
1175 | gfs2_assert_withdraw(sdp, test_bit(HIF_HOLDER, &gh->gh_iflags)); | |
1176 | gfs2_assert_withdraw(sdp, relaxed_state_ok(gl->gl_state, | |
1177 | gh->gh_state, | |
1178 | gh->gh_flags)); | |
1179 | ||
1180 | if (test_bit(HIF_FIRST, &gh->gh_iflags)) { | |
1181 | gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); | |
1182 | ||
1183 | if (glops->go_lock) { | |
1184 | gh->gh_error = glops->go_lock(gh); | |
1185 | if (gh->gh_error) { | |
1186 | spin_lock(&gl->gl_spin); | |
1187 | list_del_init(&gh->gh_list); | |
1188 | if (test_and_clear_bit(HIF_RECURSE, | |
1189 | &gh->gh_iflags)) | |
1190 | do_unrecurse(gh); | |
1191 | spin_unlock(&gl->gl_spin); | |
1192 | } | |
1193 | } | |
1194 | ||
1195 | spin_lock(&gl->gl_spin); | |
1196 | gl->gl_req_gh = NULL; | |
1197 | gl->gl_req_bh = NULL; | |
1198 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
1199 | if (test_bit(HIF_RECURSE, &gh->gh_iflags)) | |
1200 | handle_recurse(gh); | |
1201 | run_queue(gl); | |
1202 | spin_unlock(&gl->gl_spin); | |
1203 | } | |
1204 | ||
1205 | return gh->gh_error; | |
1206 | } | |
1207 | ||
1208 | static inline struct gfs2_holder * | |
1209 | find_holder_by_owner(struct list_head *head, struct task_struct *owner) | |
1210 | { | |
1211 | struct gfs2_holder *gh; | |
1212 | ||
1213 | list_for_each_entry(gh, head, gh_list) { | |
1214 | if (gh->gh_owner == owner) | |
1215 | return gh; | |
1216 | } | |
1217 | ||
1218 | return NULL; | |
1219 | } | |
1220 | ||
1221 | /** | |
1222 | * recurse_check - | |
1223 | * | |
1224 | * Make sure the new holder is compatible with the pre-existing one. | |
1225 | * | |
1226 | */ | |
1227 | ||
1228 | static int recurse_check(struct gfs2_holder *existing, struct gfs2_holder *new, | |
1229 | unsigned int state) | |
1230 | { | |
1231 | struct gfs2_sbd *sdp = existing->gh_gl->gl_sbd; | |
1232 | ||
1233 | if (gfs2_assert_warn(sdp, (new->gh_flags & LM_FLAG_ANY) || | |
1234 | !(existing->gh_flags & LM_FLAG_ANY))) | |
1235 | goto fail; | |
1236 | ||
1237 | if (gfs2_assert_warn(sdp, (existing->gh_flags & GL_LOCAL_EXCL) || | |
1238 | !(new->gh_flags & GL_LOCAL_EXCL))) | |
1239 | goto fail; | |
1240 | ||
1241 | if (gfs2_assert_warn(sdp, relaxed_state_ok(state, new->gh_state, | |
1242 | new->gh_flags))) | |
1243 | goto fail; | |
1244 | ||
1245 | return 0; | |
1246 | ||
1247 | fail: | |
d0dc80db SW |
1248 | print_symbol(KERN_WARNING "GFS2: Existing holder from %s\n", |
1249 | existing->gh_ip); | |
1250 | print_symbol(KERN_WARNING "GFS2: New holder from %s\n", new->gh_ip); | |
b3b94faa DT |
1251 | set_bit(HIF_ABORTED, &new->gh_iflags); |
1252 | return -EINVAL; | |
1253 | } | |
1254 | ||
1255 | /** | |
1256 | * add_to_queue - Add a holder to the wait queue (but look for recursion) | |
1257 | * @gh: the holder structure to add | |
1258 | * | |
1259 | */ | |
1260 | ||
1261 | static void add_to_queue(struct gfs2_holder *gh) | |
1262 | { | |
1263 | struct gfs2_glock *gl = gh->gh_gl; | |
1264 | struct gfs2_holder *existing; | |
1265 | ||
1266 | if (!gh->gh_owner) | |
1267 | goto out; | |
1268 | ||
1269 | existing = find_holder_by_owner(&gl->gl_holders, gh->gh_owner); | |
1270 | if (existing) { | |
1271 | if (recurse_check(existing, gh, gl->gl_state)) | |
1272 | return; | |
1273 | ||
1274 | list_add_tail(&gh->gh_list, &gl->gl_holders); | |
1275 | set_bit(HIF_HOLDER, &gh->gh_iflags); | |
1276 | ||
1277 | gh->gh_error = 0; | |
1278 | complete(&gh->gh_wait); | |
1279 | ||
1280 | return; | |
1281 | } | |
1282 | ||
1283 | existing = find_holder_by_owner(&gl->gl_waiters3, gh->gh_owner); | |
1284 | if (existing) { | |
1285 | if (recurse_check(existing, gh, existing->gh_state)) | |
1286 | return; | |
1287 | ||
1288 | set_bit(HIF_RECURSE, &gh->gh_iflags); | |
1289 | set_bit(HIF_RECURSE, &existing->gh_iflags); | |
1290 | ||
1291 | list_add_tail(&gh->gh_list, &gl->gl_waiters3); | |
1292 | ||
1293 | return; | |
1294 | } | |
1295 | ||
1296 | out: | |
1297 | if (gh->gh_flags & LM_FLAG_PRIORITY) | |
1298 | list_add(&gh->gh_list, &gl->gl_waiters3); | |
1299 | else | |
1300 | list_add_tail(&gh->gh_list, &gl->gl_waiters3); | |
1301 | } | |
1302 | ||
1303 | /** | |
1304 | * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock) | |
1305 | * @gh: the holder structure | |
1306 | * | |
1307 | * if (gh->gh_flags & GL_ASYNC), this never returns an error | |
1308 | * | |
1309 | * Returns: 0, GLR_TRYFAILED, or errno on failure | |
1310 | */ | |
1311 | ||
1312 | int gfs2_glock_nq(struct gfs2_holder *gh) | |
1313 | { | |
1314 | struct gfs2_glock *gl = gh->gh_gl; | |
1315 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
1316 | int error = 0; | |
1317 | ||
b3b94faa DT |
1318 | restart: |
1319 | if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) { | |
1320 | set_bit(HIF_ABORTED, &gh->gh_iflags); | |
1321 | return -EIO; | |
1322 | } | |
1323 | ||
1324 | set_bit(HIF_PROMOTE, &gh->gh_iflags); | |
1325 | ||
1326 | spin_lock(&gl->gl_spin); | |
1327 | add_to_queue(gh); | |
1328 | run_queue(gl); | |
1329 | spin_unlock(&gl->gl_spin); | |
1330 | ||
1331 | if (!(gh->gh_flags & GL_ASYNC)) { | |
1332 | error = glock_wait_internal(gh); | |
1333 | if (error == GLR_CANCELED) { | |
1334 | msleep(1000); | |
1335 | goto restart; | |
1336 | } | |
1337 | } | |
1338 | ||
1339 | clear_bit(GLF_PREFETCH, &gl->gl_flags); | |
1340 | ||
1341 | return error; | |
1342 | } | |
1343 | ||
1344 | /** | |
1345 | * gfs2_glock_poll - poll to see if an async request has been completed | |
1346 | * @gh: the holder | |
1347 | * | |
1348 | * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on | |
1349 | */ | |
1350 | ||
1351 | int gfs2_glock_poll(struct gfs2_holder *gh) | |
1352 | { | |
1353 | struct gfs2_glock *gl = gh->gh_gl; | |
1354 | int ready = 0; | |
1355 | ||
1356 | spin_lock(&gl->gl_spin); | |
1357 | ||
1358 | if (test_bit(HIF_HOLDER, &gh->gh_iflags)) | |
1359 | ready = 1; | |
1360 | else if (list_empty(&gh->gh_list)) { | |
1361 | if (gh->gh_error == GLR_CANCELED) { | |
1362 | spin_unlock(&gl->gl_spin); | |
1363 | msleep(1000); | |
1364 | if (gfs2_glock_nq(gh)) | |
1365 | return 1; | |
1366 | return 0; | |
1367 | } else | |
1368 | ready = 1; | |
1369 | } | |
1370 | ||
1371 | spin_unlock(&gl->gl_spin); | |
1372 | ||
1373 | return ready; | |
1374 | } | |
1375 | ||
1376 | /** | |
1377 | * gfs2_glock_wait - wait for a lock acquisition that ended in a GLR_ASYNC | |
1378 | * @gh: the holder structure | |
1379 | * | |
1380 | * Returns: 0, GLR_TRYFAILED, or errno on failure | |
1381 | */ | |
1382 | ||
1383 | int gfs2_glock_wait(struct gfs2_holder *gh) | |
1384 | { | |
1385 | int error; | |
1386 | ||
1387 | error = glock_wait_internal(gh); | |
1388 | if (error == GLR_CANCELED) { | |
1389 | msleep(1000); | |
1390 | gh->gh_flags &= ~GL_ASYNC; | |
1391 | error = gfs2_glock_nq(gh); | |
1392 | } | |
1393 | ||
1394 | return error; | |
1395 | } | |
1396 | ||
1397 | /** | |
1398 | * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock) | |
1399 | * @gh: the glock holder | |
1400 | * | |
1401 | */ | |
1402 | ||
1403 | void gfs2_glock_dq(struct gfs2_holder *gh) | |
1404 | { | |
1405 | struct gfs2_glock *gl = gh->gh_gl; | |
b3b94faa DT |
1406 | struct gfs2_glock_operations *glops = gl->gl_ops; |
1407 | ||
b3b94faa DT |
1408 | if (gh->gh_flags & GL_SYNC) |
1409 | set_bit(GLF_SYNC, &gl->gl_flags); | |
1410 | ||
1411 | if (gh->gh_flags & GL_NOCACHE) | |
1412 | handle_callback(gl, LM_ST_UNLOCKED); | |
1413 | ||
1414 | gfs2_glmutex_lock(gl); | |
1415 | ||
1416 | spin_lock(&gl->gl_spin); | |
1417 | list_del_init(&gh->gh_list); | |
1418 | ||
1419 | if (list_empty(&gl->gl_holders)) { | |
1420 | spin_unlock(&gl->gl_spin); | |
1421 | ||
1422 | if (glops->go_unlock) | |
1423 | glops->go_unlock(gh); | |
1424 | ||
1425 | if (test_bit(GLF_SYNC, &gl->gl_flags)) { | |
1426 | if (glops->go_sync) | |
1427 | glops->go_sync(gl, DIO_METADATA | DIO_DATA); | |
1428 | } | |
1429 | ||
1430 | gl->gl_stamp = jiffies; | |
1431 | ||
1432 | spin_lock(&gl->gl_spin); | |
1433 | } | |
1434 | ||
1435 | clear_bit(GLF_LOCK, &gl->gl_flags); | |
1436 | run_queue(gl); | |
1437 | spin_unlock(&gl->gl_spin); | |
1438 | } | |
1439 | ||
1440 | /** | |
1441 | * gfs2_glock_prefetch - Try to prefetch a glock | |
1442 | * @gl: the glock | |
1443 | * @state: the state to prefetch in | |
1444 | * @flags: flags passed to go_xmote_th() | |
1445 | * | |
1446 | */ | |
1447 | ||
1448 | void gfs2_glock_prefetch(struct gfs2_glock *gl, unsigned int state, int flags) | |
1449 | { | |
1450 | struct gfs2_glock_operations *glops = gl->gl_ops; | |
1451 | ||
1452 | spin_lock(&gl->gl_spin); | |
1453 | ||
1454 | if (test_bit(GLF_LOCK, &gl->gl_flags) || | |
1455 | !list_empty(&gl->gl_holders) || | |
1456 | !list_empty(&gl->gl_waiters1) || | |
1457 | !list_empty(&gl->gl_waiters2) || | |
1458 | !list_empty(&gl->gl_waiters3) || | |
1459 | relaxed_state_ok(gl->gl_state, state, flags)) { | |
1460 | spin_unlock(&gl->gl_spin); | |
1461 | return; | |
1462 | } | |
1463 | ||
1464 | set_bit(GLF_PREFETCH, &gl->gl_flags); | |
1465 | set_bit(GLF_LOCK, &gl->gl_flags); | |
1466 | spin_unlock(&gl->gl_spin); | |
1467 | ||
1468 | glops->go_xmote_th(gl, state, flags); | |
b3b94faa DT |
1469 | } |
1470 | ||
1471 | /** | |
1472 | * gfs2_glock_force_drop - Force a glock to be uncached | |
1473 | * @gl: the glock | |
1474 | * | |
1475 | */ | |
1476 | ||
1477 | void gfs2_glock_force_drop(struct gfs2_glock *gl) | |
1478 | { | |
1479 | struct gfs2_holder gh; | |
1480 | ||
1481 | gfs2_holder_init(gl, LM_ST_UNLOCKED, GL_NEVER_RECURSE, &gh); | |
1482 | set_bit(HIF_DEMOTE, &gh.gh_iflags); | |
1483 | ||
1484 | spin_lock(&gl->gl_spin); | |
1485 | list_add_tail(&gh.gh_list, &gl->gl_waiters2); | |
1486 | run_queue(gl); | |
1487 | spin_unlock(&gl->gl_spin); | |
1488 | ||
1489 | wait_for_completion(&gh.gh_wait); | |
1490 | gfs2_holder_uninit(&gh); | |
1491 | } | |
1492 | ||
1493 | static void greedy_work(void *data) | |
1494 | { | |
1495 | struct greedy *gr = (struct greedy *)data; | |
1496 | struct gfs2_holder *gh = &gr->gr_gh; | |
1497 | struct gfs2_glock *gl = gh->gh_gl; | |
1498 | struct gfs2_glock_operations *glops = gl->gl_ops; | |
1499 | ||
1500 | clear_bit(GLF_SKIP_WAITERS2, &gl->gl_flags); | |
1501 | ||
1502 | if (glops->go_greedy) | |
1503 | glops->go_greedy(gl); | |
1504 | ||
1505 | spin_lock(&gl->gl_spin); | |
1506 | ||
1507 | if (list_empty(&gl->gl_waiters2)) { | |
1508 | clear_bit(GLF_GREEDY, &gl->gl_flags); | |
1509 | spin_unlock(&gl->gl_spin); | |
1510 | gfs2_holder_uninit(gh); | |
1511 | kfree(gr); | |
1512 | } else { | |
1513 | gfs2_glock_hold(gl); | |
1514 | list_add_tail(&gh->gh_list, &gl->gl_waiters2); | |
1515 | run_queue(gl); | |
1516 | spin_unlock(&gl->gl_spin); | |
1517 | gfs2_glock_put(gl); | |
1518 | } | |
1519 | } | |
1520 | ||
1521 | /** | |
1522 | * gfs2_glock_be_greedy - | |
1523 | * @gl: | |
1524 | * @time: | |
1525 | * | |
1526 | * Returns: 0 if go_greedy will be called, 1 otherwise | |
1527 | */ | |
1528 | ||
1529 | int gfs2_glock_be_greedy(struct gfs2_glock *gl, unsigned int time) | |
1530 | { | |
1531 | struct greedy *gr; | |
1532 | struct gfs2_holder *gh; | |
1533 | ||
1534 | if (!time || | |
1535 | gl->gl_sbd->sd_args.ar_localcaching || | |
1536 | test_and_set_bit(GLF_GREEDY, &gl->gl_flags)) | |
1537 | return 1; | |
1538 | ||
1539 | gr = kmalloc(sizeof(struct greedy), GFP_KERNEL); | |
1540 | if (!gr) { | |
1541 | clear_bit(GLF_GREEDY, &gl->gl_flags); | |
1542 | return 1; | |
1543 | } | |
1544 | gh = &gr->gr_gh; | |
1545 | ||
1546 | gfs2_holder_init(gl, 0, GL_NEVER_RECURSE, gh); | |
1547 | set_bit(HIF_GREEDY, &gh->gh_iflags); | |
1548 | INIT_WORK(&gr->gr_work, greedy_work, gr); | |
1549 | ||
1550 | set_bit(GLF_SKIP_WAITERS2, &gl->gl_flags); | |
1551 | schedule_delayed_work(&gr->gr_work, time); | |
1552 | ||
1553 | return 0; | |
1554 | } | |
1555 | ||
b3b94faa DT |
1556 | /** |
1557 | * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it | |
1558 | * @gh: the holder structure | |
1559 | * | |
1560 | */ | |
1561 | ||
1562 | void gfs2_glock_dq_uninit(struct gfs2_holder *gh) | |
1563 | { | |
1564 | gfs2_glock_dq(gh); | |
1565 | gfs2_holder_uninit(gh); | |
1566 | } | |
1567 | ||
1568 | /** | |
1569 | * gfs2_glock_nq_num - acquire a glock based on lock number | |
1570 | * @sdp: the filesystem | |
1571 | * @number: the lock number | |
1572 | * @glops: the glock operations for the type of glock | |
1573 | * @state: the state to acquire the glock in | |
1574 | * @flags: modifier flags for the aquisition | |
1575 | * @gh: the struct gfs2_holder | |
1576 | * | |
1577 | * Returns: errno | |
1578 | */ | |
1579 | ||
1580 | int gfs2_glock_nq_num(struct gfs2_sbd *sdp, uint64_t number, | |
1581 | struct gfs2_glock_operations *glops, unsigned int state, | |
1582 | int flags, struct gfs2_holder *gh) | |
1583 | { | |
1584 | struct gfs2_glock *gl; | |
1585 | int error; | |
1586 | ||
1587 | error = gfs2_glock_get(sdp, number, glops, CREATE, &gl); | |
1588 | if (!error) { | |
1589 | error = gfs2_glock_nq_init(gl, state, flags, gh); | |
1590 | gfs2_glock_put(gl); | |
1591 | } | |
1592 | ||
1593 | return error; | |
1594 | } | |
1595 | ||
1596 | /** | |
1597 | * glock_compare - Compare two struct gfs2_glock structures for sorting | |
1598 | * @arg_a: the first structure | |
1599 | * @arg_b: the second structure | |
1600 | * | |
1601 | */ | |
1602 | ||
1603 | static int glock_compare(const void *arg_a, const void *arg_b) | |
1604 | { | |
1605 | struct gfs2_holder *gh_a = *(struct gfs2_holder **)arg_a; | |
1606 | struct gfs2_holder *gh_b = *(struct gfs2_holder **)arg_b; | |
1607 | struct lm_lockname *a = &gh_a->gh_gl->gl_name; | |
1608 | struct lm_lockname *b = &gh_b->gh_gl->gl_name; | |
1609 | int ret = 0; | |
1610 | ||
1611 | if (a->ln_number > b->ln_number) | |
1612 | ret = 1; | |
1613 | else if (a->ln_number < b->ln_number) | |
1614 | ret = -1; | |
1615 | else { | |
1616 | if (gh_a->gh_state == LM_ST_SHARED && | |
1617 | gh_b->gh_state == LM_ST_EXCLUSIVE) | |
1618 | ret = 1; | |
1619 | else if (!(gh_a->gh_flags & GL_LOCAL_EXCL) && | |
1620 | (gh_b->gh_flags & GL_LOCAL_EXCL)) | |
1621 | ret = 1; | |
1622 | } | |
1623 | ||
1624 | return ret; | |
1625 | } | |
1626 | ||
1627 | /** | |
1628 | * nq_m_sync - synchonously acquire more than one glock in deadlock free order | |
1629 | * @num_gh: the number of structures | |
1630 | * @ghs: an array of struct gfs2_holder structures | |
1631 | * | |
1632 | * Returns: 0 on success (all glocks acquired), | |
1633 | * errno on failure (no glocks acquired) | |
1634 | */ | |
1635 | ||
1636 | static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs, | |
1637 | struct gfs2_holder **p) | |
1638 | { | |
1639 | unsigned int x; | |
1640 | int error = 0; | |
1641 | ||
1642 | for (x = 0; x < num_gh; x++) | |
1643 | p[x] = &ghs[x]; | |
1644 | ||
1645 | sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL); | |
1646 | ||
1647 | for (x = 0; x < num_gh; x++) { | |
1648 | p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); | |
1649 | ||
1650 | error = gfs2_glock_nq(p[x]); | |
1651 | if (error) { | |
1652 | while (x--) | |
1653 | gfs2_glock_dq(p[x]); | |
1654 | break; | |
1655 | } | |
1656 | } | |
1657 | ||
1658 | return error; | |
1659 | } | |
1660 | ||
1661 | /** | |
1662 | * gfs2_glock_nq_m - acquire multiple glocks | |
1663 | * @num_gh: the number of structures | |
1664 | * @ghs: an array of struct gfs2_holder structures | |
1665 | * | |
1666 | * Figure out how big an impact this function has. Either: | |
1667 | * 1) Replace this code with code that calls gfs2_glock_prefetch() | |
1668 | * 2) Forget async stuff and just call nq_m_sync() | |
1669 | * 3) Leave it like it is | |
1670 | * | |
1671 | * Returns: 0 on success (all glocks acquired), | |
1672 | * errno on failure (no glocks acquired) | |
1673 | */ | |
1674 | ||
1675 | int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1676 | { | |
1677 | int *e; | |
1678 | unsigned int x; | |
1679 | int borked = 0, serious = 0; | |
1680 | int error = 0; | |
1681 | ||
1682 | if (!num_gh) | |
1683 | return 0; | |
1684 | ||
1685 | if (num_gh == 1) { | |
1686 | ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC); | |
1687 | return gfs2_glock_nq(ghs); | |
1688 | } | |
1689 | ||
1690 | e = kcalloc(num_gh, sizeof(struct gfs2_holder *), GFP_KERNEL); | |
1691 | if (!e) | |
1692 | return -ENOMEM; | |
1693 | ||
1694 | for (x = 0; x < num_gh; x++) { | |
1695 | ghs[x].gh_flags |= LM_FLAG_TRY | GL_ASYNC; | |
1696 | error = gfs2_glock_nq(&ghs[x]); | |
1697 | if (error) { | |
1698 | borked = 1; | |
1699 | serious = error; | |
1700 | num_gh = x; | |
1701 | break; | |
1702 | } | |
1703 | } | |
1704 | ||
1705 | for (x = 0; x < num_gh; x++) { | |
1706 | error = e[x] = glock_wait_internal(&ghs[x]); | |
1707 | if (error) { | |
1708 | borked = 1; | |
1709 | if (error != GLR_TRYFAILED && error != GLR_CANCELED) | |
1710 | serious = error; | |
1711 | } | |
1712 | } | |
1713 | ||
1714 | if (!borked) { | |
1715 | kfree(e); | |
1716 | return 0; | |
1717 | } | |
1718 | ||
1719 | for (x = 0; x < num_gh; x++) | |
1720 | if (!e[x]) | |
1721 | gfs2_glock_dq(&ghs[x]); | |
1722 | ||
1723 | if (serious) | |
1724 | error = serious; | |
1725 | else { | |
1726 | for (x = 0; x < num_gh; x++) | |
1727 | gfs2_holder_reinit(ghs[x].gh_state, ghs[x].gh_flags, | |
1728 | &ghs[x]); | |
1729 | error = nq_m_sync(num_gh, ghs, (struct gfs2_holder **)e); | |
1730 | } | |
1731 | ||
1732 | kfree(e); | |
1733 | ||
1734 | return error; | |
1735 | } | |
1736 | ||
1737 | /** | |
1738 | * gfs2_glock_dq_m - release multiple glocks | |
1739 | * @num_gh: the number of structures | |
1740 | * @ghs: an array of struct gfs2_holder structures | |
1741 | * | |
1742 | */ | |
1743 | ||
1744 | void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1745 | { | |
1746 | unsigned int x; | |
1747 | ||
1748 | for (x = 0; x < num_gh; x++) | |
1749 | gfs2_glock_dq(&ghs[x]); | |
1750 | } | |
1751 | ||
1752 | /** | |
1753 | * gfs2_glock_dq_uninit_m - release multiple glocks | |
1754 | * @num_gh: the number of structures | |
1755 | * @ghs: an array of struct gfs2_holder structures | |
1756 | * | |
1757 | */ | |
1758 | ||
1759 | void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs) | |
1760 | { | |
1761 | unsigned int x; | |
1762 | ||
1763 | for (x = 0; x < num_gh; x++) | |
1764 | gfs2_glock_dq_uninit(&ghs[x]); | |
1765 | } | |
1766 | ||
1767 | /** | |
1768 | * gfs2_glock_prefetch_num - prefetch a glock based on lock number | |
1769 | * @sdp: the filesystem | |
1770 | * @number: the lock number | |
1771 | * @glops: the glock operations for the type of glock | |
1772 | * @state: the state to acquire the glock in | |
1773 | * @flags: modifier flags for the aquisition | |
1774 | * | |
1775 | * Returns: errno | |
1776 | */ | |
1777 | ||
1778 | void gfs2_glock_prefetch_num(struct gfs2_sbd *sdp, uint64_t number, | |
1779 | struct gfs2_glock_operations *glops, | |
1780 | unsigned int state, int flags) | |
1781 | { | |
1782 | struct gfs2_glock *gl; | |
1783 | int error; | |
1784 | ||
1785 | if (atomic_read(&sdp->sd_reclaim_count) < | |
1786 | gfs2_tune_get(sdp, gt_reclaim_limit)) { | |
1787 | error = gfs2_glock_get(sdp, number, glops, CREATE, &gl); | |
1788 | if (!error) { | |
1789 | gfs2_glock_prefetch(gl, state, flags); | |
1790 | gfs2_glock_put(gl); | |
1791 | } | |
1792 | } | |
1793 | } | |
1794 | ||
1795 | /** | |
1796 | * gfs2_lvb_hold - attach a LVB from a glock | |
1797 | * @gl: The glock in question | |
1798 | * | |
1799 | */ | |
1800 | ||
1801 | int gfs2_lvb_hold(struct gfs2_glock *gl) | |
1802 | { | |
1803 | int error; | |
1804 | ||
1805 | gfs2_glmutex_lock(gl); | |
1806 | ||
1807 | if (!atomic_read(&gl->gl_lvb_count)) { | |
1808 | error = gfs2_lm_hold_lvb(gl->gl_sbd, gl->gl_lock, &gl->gl_lvb); | |
1809 | if (error) { | |
1810 | gfs2_glmutex_unlock(gl); | |
1811 | return error; | |
1812 | } | |
1813 | gfs2_glock_hold(gl); | |
1814 | } | |
1815 | atomic_inc(&gl->gl_lvb_count); | |
1816 | ||
1817 | gfs2_glmutex_unlock(gl); | |
1818 | ||
1819 | return 0; | |
1820 | } | |
1821 | ||
1822 | /** | |
1823 | * gfs2_lvb_unhold - detach a LVB from a glock | |
1824 | * @gl: The glock in question | |
1825 | * | |
1826 | */ | |
1827 | ||
1828 | void gfs2_lvb_unhold(struct gfs2_glock *gl) | |
1829 | { | |
1830 | gfs2_glock_hold(gl); | |
1831 | gfs2_glmutex_lock(gl); | |
1832 | ||
1833 | gfs2_assert(gl->gl_sbd, atomic_read(&gl->gl_lvb_count) > 0); | |
1834 | if (atomic_dec_and_test(&gl->gl_lvb_count)) { | |
1835 | gfs2_lm_unhold_lvb(gl->gl_sbd, gl->gl_lock, gl->gl_lvb); | |
1836 | gl->gl_lvb = NULL; | |
1837 | gfs2_glock_put(gl); | |
1838 | } | |
1839 | ||
1840 | gfs2_glmutex_unlock(gl); | |
1841 | gfs2_glock_put(gl); | |
1842 | } | |
1843 | ||
1844 | void gfs2_lvb_sync(struct gfs2_glock *gl) | |
1845 | { | |
1846 | gfs2_glmutex_lock(gl); | |
1847 | ||
1848 | gfs2_assert(gl->gl_sbd, atomic_read(&gl->gl_lvb_count)); | |
1849 | if (!gfs2_assert_warn(gl->gl_sbd, gfs2_glock_is_held_excl(gl))) | |
1850 | gfs2_lm_sync_lvb(gl->gl_sbd, gl->gl_lock, gl->gl_lvb); | |
1851 | ||
1852 | gfs2_glmutex_unlock(gl); | |
1853 | } | |
1854 | ||
1855 | static void blocking_cb(struct gfs2_sbd *sdp, struct lm_lockname *name, | |
1856 | unsigned int state) | |
1857 | { | |
1858 | struct gfs2_glock *gl; | |
1859 | ||
1860 | gl = gfs2_glock_find(sdp, name); | |
1861 | if (!gl) | |
1862 | return; | |
1863 | ||
1864 | if (gl->gl_ops->go_callback) | |
1865 | gl->gl_ops->go_callback(gl, state); | |
1866 | handle_callback(gl, state); | |
1867 | ||
1868 | spin_lock(&gl->gl_spin); | |
1869 | run_queue(gl); | |
1870 | spin_unlock(&gl->gl_spin); | |
1871 | ||
1872 | gfs2_glock_put(gl); | |
1873 | } | |
1874 | ||
1875 | /** | |
1876 | * gfs2_glock_cb - Callback used by locking module | |
1877 | * @fsdata: Pointer to the superblock | |
1878 | * @type: Type of callback | |
1879 | * @data: Type dependent data pointer | |
1880 | * | |
1881 | * Called by the locking module when it wants to tell us something. | |
1882 | * Either we need to drop a lock, one of our ASYNC requests completed, or | |
1883 | * a journal from another client needs to be recovered. | |
1884 | */ | |
1885 | ||
1886 | void gfs2_glock_cb(lm_fsdata_t *fsdata, unsigned int type, void *data) | |
1887 | { | |
1888 | struct gfs2_sbd *sdp = (struct gfs2_sbd *)fsdata; | |
1889 | ||
b3b94faa DT |
1890 | switch (type) { |
1891 | case LM_CB_NEED_E: | |
1892 | blocking_cb(sdp, (struct lm_lockname *)data, LM_ST_UNLOCKED); | |
1893 | return; | |
1894 | ||
1895 | case LM_CB_NEED_D: | |
1896 | blocking_cb(sdp, (struct lm_lockname *)data, LM_ST_DEFERRED); | |
1897 | return; | |
1898 | ||
1899 | case LM_CB_NEED_S: | |
1900 | blocking_cb(sdp, (struct lm_lockname *)data, LM_ST_SHARED); | |
1901 | return; | |
1902 | ||
1903 | case LM_CB_ASYNC: { | |
1904 | struct lm_async_cb *async = (struct lm_async_cb *)data; | |
1905 | struct gfs2_glock *gl; | |
1906 | ||
1907 | gl = gfs2_glock_find(sdp, &async->lc_name); | |
1908 | if (gfs2_assert_warn(sdp, gl)) | |
1909 | return; | |
1910 | if (!gfs2_assert_warn(sdp, gl->gl_req_bh)) | |
1911 | gl->gl_req_bh(gl, async->lc_ret); | |
1912 | gfs2_glock_put(gl); | |
1913 | ||
1914 | return; | |
1915 | } | |
1916 | ||
1917 | case LM_CB_NEED_RECOVERY: | |
1918 | gfs2_jdesc_make_dirty(sdp, *(unsigned int *)data); | |
1919 | if (sdp->sd_recoverd_process) | |
1920 | wake_up_process(sdp->sd_recoverd_process); | |
1921 | return; | |
1922 | ||
1923 | case LM_CB_DROPLOCKS: | |
1924 | gfs2_gl_hash_clear(sdp, NO_WAIT); | |
1925 | gfs2_quota_scan(sdp); | |
1926 | return; | |
1927 | ||
1928 | default: | |
1929 | gfs2_assert_warn(sdp, 0); | |
1930 | return; | |
1931 | } | |
1932 | } | |
1933 | ||
1934 | /** | |
1935 | * gfs2_try_toss_inode - try to remove a particular inode struct from cache | |
1936 | * sdp: the filesystem | |
1937 | * inum: the inode number | |
1938 | * | |
1939 | */ | |
1940 | ||
1941 | void gfs2_try_toss_inode(struct gfs2_sbd *sdp, struct gfs2_inum *inum) | |
1942 | { | |
1943 | struct gfs2_glock *gl; | |
1944 | struct gfs2_inode *ip; | |
1945 | int error; | |
1946 | ||
1947 | error = gfs2_glock_get(sdp, inum->no_addr, &gfs2_inode_glops, | |
1948 | NO_CREATE, &gl); | |
1949 | if (error || !gl) | |
1950 | return; | |
1951 | ||
1952 | if (!gfs2_glmutex_trylock(gl)) | |
1953 | goto out; | |
1954 | ||
5c676f6d | 1955 | ip = gl->gl_object; |
b3b94faa DT |
1956 | if (!ip) |
1957 | goto out_unlock; | |
1958 | ||
1959 | if (atomic_read(&ip->i_count)) | |
1960 | goto out_unlock; | |
1961 | ||
1962 | gfs2_inode_destroy(ip); | |
1963 | ||
1964 | out_unlock: | |
1965 | gfs2_glmutex_unlock(gl); | |
1966 | ||
1967 | out: | |
1968 | gfs2_glock_put(gl); | |
1969 | } | |
1970 | ||
1971 | /** | |
1972 | * gfs2_iopen_go_callback - Try to kick the inode/vnode associated with an | |
1973 | * iopen glock from memory | |
1974 | * @io_gl: the iopen glock | |
1975 | * @state: the state into which the glock should be put | |
1976 | * | |
1977 | */ | |
1978 | ||
1979 | void gfs2_iopen_go_callback(struct gfs2_glock *io_gl, unsigned int state) | |
1980 | { | |
1981 | struct gfs2_glock *i_gl; | |
1982 | ||
1983 | if (state != LM_ST_UNLOCKED) | |
1984 | return; | |
1985 | ||
1986 | spin_lock(&io_gl->gl_spin); | |
5c676f6d | 1987 | i_gl = io_gl->gl_object; |
b3b94faa DT |
1988 | if (i_gl) { |
1989 | gfs2_glock_hold(i_gl); | |
1990 | spin_unlock(&io_gl->gl_spin); | |
1991 | } else { | |
1992 | spin_unlock(&io_gl->gl_spin); | |
1993 | return; | |
1994 | } | |
1995 | ||
1996 | if (gfs2_glmutex_trylock(i_gl)) { | |
5c676f6d | 1997 | struct gfs2_inode *ip = i_gl->gl_object; |
b3b94faa DT |
1998 | if (ip) { |
1999 | gfs2_try_toss_vnode(ip); | |
2000 | gfs2_glmutex_unlock(i_gl); | |
2001 | gfs2_glock_schedule_for_reclaim(i_gl); | |
2002 | goto out; | |
2003 | } | |
2004 | gfs2_glmutex_unlock(i_gl); | |
2005 | } | |
2006 | ||
2007 | out: | |
2008 | gfs2_glock_put(i_gl); | |
2009 | } | |
2010 | ||
2011 | /** | |
2012 | * demote_ok - Check to see if it's ok to unlock a glock | |
2013 | * @gl: the glock | |
2014 | * | |
2015 | * Returns: 1 if it's ok | |
2016 | */ | |
2017 | ||
2018 | static int demote_ok(struct gfs2_glock *gl) | |
2019 | { | |
2020 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
2021 | struct gfs2_glock_operations *glops = gl->gl_ops; | |
2022 | int demote = 1; | |
2023 | ||
2024 | if (test_bit(GLF_STICKY, &gl->gl_flags)) | |
2025 | demote = 0; | |
2026 | else if (test_bit(GLF_PREFETCH, &gl->gl_flags)) | |
2027 | demote = time_after_eq(jiffies, | |
2028 | gl->gl_stamp + | |
2029 | gfs2_tune_get(sdp, gt_prefetch_secs) * HZ); | |
2030 | else if (glops->go_demote_ok) | |
2031 | demote = glops->go_demote_ok(gl); | |
2032 | ||
2033 | return demote; | |
2034 | } | |
2035 | ||
2036 | /** | |
2037 | * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list | |
2038 | * @gl: the glock | |
2039 | * | |
2040 | */ | |
2041 | ||
2042 | void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl) | |
2043 | { | |
2044 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
2045 | ||
2046 | spin_lock(&sdp->sd_reclaim_lock); | |
2047 | if (list_empty(&gl->gl_reclaim)) { | |
2048 | gfs2_glock_hold(gl); | |
2049 | list_add(&gl->gl_reclaim, &sdp->sd_reclaim_list); | |
2050 | atomic_inc(&sdp->sd_reclaim_count); | |
2051 | } | |
2052 | spin_unlock(&sdp->sd_reclaim_lock); | |
2053 | ||
2054 | wake_up(&sdp->sd_reclaim_wq); | |
2055 | } | |
2056 | ||
2057 | /** | |
2058 | * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list | |
2059 | * @sdp: the filesystem | |
2060 | * | |
2061 | * Called from gfs2_glockd() glock reclaim daemon, or when promoting a | |
2062 | * different glock and we notice that there are a lot of glocks in the | |
2063 | * reclaim list. | |
2064 | * | |
2065 | */ | |
2066 | ||
2067 | void gfs2_reclaim_glock(struct gfs2_sbd *sdp) | |
2068 | { | |
2069 | struct gfs2_glock *gl; | |
2070 | ||
2071 | spin_lock(&sdp->sd_reclaim_lock); | |
2072 | if (list_empty(&sdp->sd_reclaim_list)) { | |
2073 | spin_unlock(&sdp->sd_reclaim_lock); | |
2074 | return; | |
2075 | } | |
2076 | gl = list_entry(sdp->sd_reclaim_list.next, | |
2077 | struct gfs2_glock, gl_reclaim); | |
2078 | list_del_init(&gl->gl_reclaim); | |
2079 | spin_unlock(&sdp->sd_reclaim_lock); | |
2080 | ||
2081 | atomic_dec(&sdp->sd_reclaim_count); | |
2082 | atomic_inc(&sdp->sd_reclaimed); | |
2083 | ||
2084 | if (gfs2_glmutex_trylock(gl)) { | |
2085 | if (gl->gl_ops == &gfs2_inode_glops) { | |
5c676f6d | 2086 | struct gfs2_inode *ip = gl->gl_object; |
b3b94faa DT |
2087 | if (ip && !atomic_read(&ip->i_count)) |
2088 | gfs2_inode_destroy(ip); | |
2089 | } | |
2090 | if (queue_empty(gl, &gl->gl_holders) && | |
2091 | gl->gl_state != LM_ST_UNLOCKED && | |
2092 | demote_ok(gl)) | |
2093 | handle_callback(gl, LM_ST_UNLOCKED); | |
2094 | gfs2_glmutex_unlock(gl); | |
2095 | } | |
2096 | ||
2097 | gfs2_glock_put(gl); | |
2098 | } | |
2099 | ||
2100 | /** | |
2101 | * examine_bucket - Call a function for glock in a hash bucket | |
2102 | * @examiner: the function | |
2103 | * @sdp: the filesystem | |
2104 | * @bucket: the bucket | |
2105 | * | |
2106 | * Returns: 1 if the bucket has entries | |
2107 | */ | |
2108 | ||
2109 | static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp, | |
2110 | struct gfs2_gl_hash_bucket *bucket) | |
2111 | { | |
2112 | struct glock_plug plug; | |
2113 | struct list_head *tmp; | |
2114 | struct gfs2_glock *gl; | |
2115 | int entries; | |
2116 | ||
2117 | /* Add "plug" to end of bucket list, work back up list from there */ | |
2118 | memset(&plug.gl_flags, 0, sizeof(unsigned long)); | |
2119 | set_bit(GLF_PLUG, &plug.gl_flags); | |
2120 | ||
2121 | write_lock(&bucket->hb_lock); | |
2122 | list_add(&plug.gl_list, &bucket->hb_list); | |
2123 | write_unlock(&bucket->hb_lock); | |
2124 | ||
2125 | for (;;) { | |
2126 | write_lock(&bucket->hb_lock); | |
2127 | ||
2128 | for (;;) { | |
2129 | tmp = plug.gl_list.next; | |
2130 | ||
2131 | if (tmp == &bucket->hb_list) { | |
2132 | list_del(&plug.gl_list); | |
2133 | entries = !list_empty(&bucket->hb_list); | |
2134 | write_unlock(&bucket->hb_lock); | |
2135 | return entries; | |
2136 | } | |
2137 | gl = list_entry(tmp, struct gfs2_glock, gl_list); | |
2138 | ||
2139 | /* Move plug up list */ | |
2140 | list_move(&plug.gl_list, &gl->gl_list); | |
2141 | ||
2142 | if (test_bit(GLF_PLUG, &gl->gl_flags)) | |
2143 | continue; | |
2144 | ||
2145 | /* examiner() must glock_put() */ | |
2146 | gfs2_glock_hold(gl); | |
2147 | ||
2148 | break; | |
2149 | } | |
2150 | ||
2151 | write_unlock(&bucket->hb_lock); | |
2152 | ||
2153 | examiner(gl); | |
2154 | } | |
2155 | } | |
2156 | ||
2157 | /** | |
2158 | * scan_glock - look at a glock and see if we can reclaim it | |
2159 | * @gl: the glock to look at | |
2160 | * | |
2161 | */ | |
2162 | ||
2163 | static void scan_glock(struct gfs2_glock *gl) | |
2164 | { | |
2165 | if (gfs2_glmutex_trylock(gl)) { | |
2166 | if (gl->gl_ops == &gfs2_inode_glops) { | |
5c676f6d | 2167 | struct gfs2_inode *ip = gl->gl_object; |
b3b94faa DT |
2168 | if (ip && !atomic_read(&ip->i_count)) |
2169 | goto out_schedule; | |
2170 | } | |
2171 | if (queue_empty(gl, &gl->gl_holders) && | |
2172 | gl->gl_state != LM_ST_UNLOCKED && | |
2173 | demote_ok(gl)) | |
2174 | goto out_schedule; | |
2175 | ||
2176 | gfs2_glmutex_unlock(gl); | |
2177 | } | |
2178 | ||
2179 | gfs2_glock_put(gl); | |
2180 | ||
2181 | return; | |
2182 | ||
2183 | out_schedule: | |
2184 | gfs2_glmutex_unlock(gl); | |
2185 | gfs2_glock_schedule_for_reclaim(gl); | |
2186 | gfs2_glock_put(gl); | |
2187 | } | |
2188 | ||
2189 | /** | |
2190 | * gfs2_scand_internal - Look for glocks and inodes to toss from memory | |
2191 | * @sdp: the filesystem | |
2192 | * | |
2193 | */ | |
2194 | ||
2195 | void gfs2_scand_internal(struct gfs2_sbd *sdp) | |
2196 | { | |
2197 | unsigned int x; | |
2198 | ||
2199 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { | |
2200 | examine_bucket(scan_glock, sdp, &sdp->sd_gl_hash[x]); | |
2201 | cond_resched(); | |
2202 | } | |
2203 | } | |
2204 | ||
2205 | /** | |
2206 | * clear_glock - look at a glock and see if we can free it from glock cache | |
2207 | * @gl: the glock to look at | |
2208 | * | |
2209 | */ | |
2210 | ||
2211 | static void clear_glock(struct gfs2_glock *gl) | |
2212 | { | |
2213 | struct gfs2_sbd *sdp = gl->gl_sbd; | |
2214 | int released; | |
2215 | ||
2216 | spin_lock(&sdp->sd_reclaim_lock); | |
2217 | if (!list_empty(&gl->gl_reclaim)) { | |
2218 | list_del_init(&gl->gl_reclaim); | |
2219 | atomic_dec(&sdp->sd_reclaim_count); | |
2220 | released = gfs2_glock_put(gl); | |
2221 | gfs2_assert(sdp, !released); | |
2222 | } | |
2223 | spin_unlock(&sdp->sd_reclaim_lock); | |
2224 | ||
2225 | if (gfs2_glmutex_trylock(gl)) { | |
2226 | if (gl->gl_ops == &gfs2_inode_glops) { | |
5c676f6d | 2227 | struct gfs2_inode *ip = gl->gl_object; |
b3b94faa DT |
2228 | if (ip && !atomic_read(&ip->i_count)) |
2229 | gfs2_inode_destroy(ip); | |
2230 | } | |
2231 | if (queue_empty(gl, &gl->gl_holders) && | |
2232 | gl->gl_state != LM_ST_UNLOCKED) | |
2233 | handle_callback(gl, LM_ST_UNLOCKED); | |
2234 | ||
2235 | gfs2_glmutex_unlock(gl); | |
2236 | } | |
2237 | ||
2238 | gfs2_glock_put(gl); | |
2239 | } | |
2240 | ||
2241 | /** | |
2242 | * gfs2_gl_hash_clear - Empty out the glock hash table | |
2243 | * @sdp: the filesystem | |
2244 | * @wait: wait until it's all gone | |
2245 | * | |
2246 | * Called when unmounting the filesystem, or when inter-node lock manager | |
2247 | * requests DROPLOCKS because it is running out of capacity. | |
2248 | */ | |
2249 | ||
2250 | void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait) | |
2251 | { | |
2252 | unsigned long t; | |
2253 | unsigned int x; | |
2254 | int cont; | |
2255 | ||
2256 | t = jiffies; | |
2257 | ||
2258 | for (;;) { | |
2259 | cont = 0; | |
2260 | ||
2261 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) | |
2262 | if (examine_bucket(clear_glock, sdp, | |
2263 | &sdp->sd_gl_hash[x])) | |
2264 | cont = 1; | |
2265 | ||
2266 | if (!wait || !cont) | |
2267 | break; | |
2268 | ||
2269 | if (time_after_eq(jiffies, | |
2270 | t + gfs2_tune_get(sdp, gt_stall_secs) * HZ)) { | |
2271 | fs_warn(sdp, "Unmount seems to be stalled. " | |
2272 | "Dumping lock state...\n"); | |
2273 | gfs2_dump_lockstate(sdp); | |
2274 | t = jiffies; | |
2275 | } | |
2276 | ||
2277 | /* invalidate_inodes() requires that the sb inodes list | |
2278 | not change, but an async completion callback for an | |
2279 | unlock can occur which does glock_put() which | |
2280 | can call iput() which will change the sb inodes list. | |
2281 | invalidate_inodes_mutex prevents glock_put()'s during | |
2282 | an invalidate_inodes() */ | |
2283 | ||
f55ab26a | 2284 | mutex_lock(&sdp->sd_invalidate_inodes_mutex); |
b3b94faa | 2285 | invalidate_inodes(sdp->sd_vfs); |
f55ab26a | 2286 | mutex_unlock(&sdp->sd_invalidate_inodes_mutex); |
b3b94faa DT |
2287 | yield(); |
2288 | } | |
2289 | } | |
2290 | ||
2291 | /* | |
2292 | * Diagnostic routines to help debug distributed deadlock | |
2293 | */ | |
2294 | ||
2295 | /** | |
2296 | * dump_holder - print information about a glock holder | |
2297 | * @str: a string naming the type of holder | |
2298 | * @gh: the glock holder | |
2299 | * | |
2300 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
2301 | */ | |
2302 | ||
2303 | static int dump_holder(char *str, struct gfs2_holder *gh) | |
2304 | { | |
2305 | unsigned int x; | |
2306 | int error = -ENOBUFS; | |
2307 | ||
d92a8d48 SW |
2308 | printk(KERN_INFO " %s\n", str); |
2309 | printk(KERN_INFO " owner = %ld\n", | |
b3b94faa | 2310 | (gh->gh_owner) ? (long)gh->gh_owner->pid : -1); |
d92a8d48 SW |
2311 | printk(KERN_INFO " gh_state = %u\n", gh->gh_state); |
2312 | printk(KERN_INFO " gh_flags ="); | |
b3b94faa DT |
2313 | for (x = 0; x < 32; x++) |
2314 | if (gh->gh_flags & (1 << x)) | |
2315 | printk(" %u", x); | |
2316 | printk(" \n"); | |
d92a8d48 SW |
2317 | printk(KERN_INFO " error = %d\n", gh->gh_error); |
2318 | printk(KERN_INFO " gh_iflags ="); | |
b3b94faa DT |
2319 | for (x = 0; x < 32; x++) |
2320 | if (test_bit(x, &gh->gh_iflags)) | |
2321 | printk(" %u", x); | |
2322 | printk(" \n"); | |
d0dc80db | 2323 | print_symbol(KERN_INFO " initialized at: %s\n", gh->gh_ip); |
b3b94faa DT |
2324 | |
2325 | error = 0; | |
2326 | ||
2327 | return error; | |
2328 | } | |
2329 | ||
2330 | /** | |
2331 | * dump_inode - print information about an inode | |
2332 | * @ip: the inode | |
2333 | * | |
2334 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
2335 | */ | |
2336 | ||
2337 | static int dump_inode(struct gfs2_inode *ip) | |
2338 | { | |
2339 | unsigned int x; | |
2340 | int error = -ENOBUFS; | |
2341 | ||
d92a8d48 SW |
2342 | printk(KERN_INFO " Inode:\n"); |
2343 | printk(KERN_INFO " num = %llu %llu\n", | |
b3b94faa | 2344 | ip->i_num.no_formal_ino, ip->i_num.no_addr); |
d92a8d48 SW |
2345 | printk(KERN_INFO " type = %u\n", IF2DT(ip->i_di.di_mode)); |
2346 | printk(KERN_INFO " i_count = %d\n", atomic_read(&ip->i_count)); | |
2347 | printk(KERN_INFO " i_flags ="); | |
b3b94faa DT |
2348 | for (x = 0; x < 32; x++) |
2349 | if (test_bit(x, &ip->i_flags)) | |
2350 | printk(" %u", x); | |
2351 | printk(" \n"); | |
d92a8d48 | 2352 | printk(KERN_INFO " vnode = %s\n", (ip->i_vnode) ? "yes" : "no"); |
b3b94faa DT |
2353 | |
2354 | error = 0; | |
2355 | ||
2356 | return error; | |
2357 | } | |
2358 | ||
2359 | /** | |
2360 | * dump_glock - print information about a glock | |
2361 | * @gl: the glock | |
2362 | * @count: where we are in the buffer | |
2363 | * | |
2364 | * Returns: 0 on success, -ENOBUFS when we run out of space | |
2365 | */ | |
2366 | ||
2367 | static int dump_glock(struct gfs2_glock *gl) | |
2368 | { | |
2369 | struct gfs2_holder *gh; | |
2370 | unsigned int x; | |
2371 | int error = -ENOBUFS; | |
2372 | ||
2373 | spin_lock(&gl->gl_spin); | |
2374 | ||
d92a8d48 | 2375 | printk(KERN_INFO "Glock (%u, %llu)\n", |
b3b94faa DT |
2376 | gl->gl_name.ln_type, |
2377 | gl->gl_name.ln_number); | |
d92a8d48 | 2378 | printk(KERN_INFO " gl_flags ="); |
b3b94faa DT |
2379 | for (x = 0; x < 32; x++) |
2380 | if (test_bit(x, &gl->gl_flags)) | |
2381 | printk(" %u", x); | |
2382 | printk(" \n"); | |
d92a8d48 SW |
2383 | printk(KERN_INFO " gl_ref = %d\n", atomic_read(&gl->gl_ref.refcount)); |
2384 | printk(KERN_INFO " gl_state = %u\n", gl->gl_state); | |
2385 | printk(KERN_INFO " req_gh = %s\n", (gl->gl_req_gh) ? "yes" : "no"); | |
2386 | printk(KERN_INFO " req_bh = %s\n", (gl->gl_req_bh) ? "yes" : "no"); | |
2387 | printk(KERN_INFO " lvb_count = %d\n", atomic_read(&gl->gl_lvb_count)); | |
2388 | printk(KERN_INFO " object = %s\n", (gl->gl_object) ? "yes" : "no"); | |
2389 | printk(KERN_INFO " le = %s\n", | |
b3b94faa | 2390 | (list_empty(&gl->gl_le.le_list)) ? "no" : "yes"); |
d92a8d48 | 2391 | printk(KERN_INFO " reclaim = %s\n", |
b3b94faa DT |
2392 | (list_empty(&gl->gl_reclaim)) ? "no" : "yes"); |
2393 | if (gl->gl_aspace) | |
d92a8d48 | 2394 | printk(KERN_INFO " aspace = %lu\n", |
b3b94faa DT |
2395 | gl->gl_aspace->i_mapping->nrpages); |
2396 | else | |
d92a8d48 SW |
2397 | printk(KERN_INFO " aspace = no\n"); |
2398 | printk(KERN_INFO " ail = %d\n", atomic_read(&gl->gl_ail_count)); | |
b3b94faa DT |
2399 | if (gl->gl_req_gh) { |
2400 | error = dump_holder("Request", gl->gl_req_gh); | |
2401 | if (error) | |
2402 | goto out; | |
2403 | } | |
2404 | list_for_each_entry(gh, &gl->gl_holders, gh_list) { | |
2405 | error = dump_holder("Holder", gh); | |
2406 | if (error) | |
2407 | goto out; | |
2408 | } | |
2409 | list_for_each_entry(gh, &gl->gl_waiters1, gh_list) { | |
2410 | error = dump_holder("Waiter1", gh); | |
2411 | if (error) | |
2412 | goto out; | |
2413 | } | |
2414 | list_for_each_entry(gh, &gl->gl_waiters2, gh_list) { | |
2415 | error = dump_holder("Waiter2", gh); | |
2416 | if (error) | |
2417 | goto out; | |
2418 | } | |
2419 | list_for_each_entry(gh, &gl->gl_waiters3, gh_list) { | |
2420 | error = dump_holder("Waiter3", gh); | |
2421 | if (error) | |
2422 | goto out; | |
2423 | } | |
5c676f6d | 2424 | if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object) { |
b3b94faa DT |
2425 | if (!test_bit(GLF_LOCK, &gl->gl_flags) && |
2426 | list_empty(&gl->gl_holders)) { | |
5c676f6d | 2427 | error = dump_inode(gl->gl_object); |
b3b94faa DT |
2428 | if (error) |
2429 | goto out; | |
2430 | } else { | |
2431 | error = -ENOBUFS; | |
d92a8d48 | 2432 | printk(KERN_INFO " Inode: busy\n"); |
b3b94faa DT |
2433 | } |
2434 | } | |
2435 | ||
2436 | error = 0; | |
2437 | ||
2438 | out: | |
2439 | spin_unlock(&gl->gl_spin); | |
2440 | ||
2441 | return error; | |
2442 | } | |
2443 | ||
2444 | /** | |
2445 | * gfs2_dump_lockstate - print out the current lockstate | |
2446 | * @sdp: the filesystem | |
2447 | * @ub: the buffer to copy the information into | |
2448 | * | |
2449 | * If @ub is NULL, dump the lockstate to the console. | |
2450 | * | |
2451 | */ | |
2452 | ||
2453 | int gfs2_dump_lockstate(struct gfs2_sbd *sdp) | |
2454 | { | |
2455 | struct gfs2_gl_hash_bucket *bucket; | |
2456 | struct gfs2_glock *gl; | |
2457 | unsigned int x; | |
2458 | int error = 0; | |
2459 | ||
2460 | for (x = 0; x < GFS2_GL_HASH_SIZE; x++) { | |
2461 | bucket = &sdp->sd_gl_hash[x]; | |
2462 | ||
2463 | read_lock(&bucket->hb_lock); | |
2464 | ||
2465 | list_for_each_entry(gl, &bucket->hb_list, gl_list) { | |
2466 | if (test_bit(GLF_PLUG, &gl->gl_flags)) | |
2467 | continue; | |
2468 | ||
2469 | error = dump_glock(gl); | |
2470 | if (error) | |
2471 | break; | |
2472 | } | |
2473 | ||
2474 | read_unlock(&bucket->hb_lock); | |
2475 | ||
2476 | if (error) | |
2477 | break; | |
2478 | } | |
2479 | ||
2480 | ||
2481 | return error; | |
2482 | } | |
2483 |